#1182: Consolidate Preconditions use and minor cleanup

By: Doc <nachito94@msn.com>

paper-server/README.md

@@ -152,19 +152,33 @@ if (false && !this.world.isClientSide && !this.isDead && (d0*d0) + d1 + (d2*d2)
     this.h();
 }
 ```
-
+* For checks related to API where an exception needs to be thrown in a specific case we recommend use the package `Preconditions`
-* When adding a validation check, this applies everywhere not just in Minecraft classes, see if the Validate package has a better, more concise method you can use instead.
+  * For checking arguments we recommend using `Preconditions#checkArgument` where a failing check should throw a `IllegalArgumentException`
-    * The Preconditions package works just as well. Either are acceptable; though these are, by no means, the only accepted validation strategies.
+    * We recommend using this to ensure the behaviour of `@NotNull` in the Bukkit API
+  * For checking arguments we recommend using `Preconditions#checkState` where a failing check should throw a `IllegalStateException`
 
 __For example, you should use:__
 ```java
-Validate.notNull(sender, "Sender cannot be null");
+private Object messenger;
+
+public void sendMessage(Sender sender, String message) {
+    Preconditions.checkArgument(sender != null, "sender cannot be null");
+    Preconditions.checkState(this.messenger != null, "The messenger instance cannot be used")
+}
 ```
 __Instead of:__
 ```java
+private Object messenger;
+
+public void sendMessage(Sender sender, String message) {
     if (sender == null) {
         throw new IllegalArgumentException("Sender cannot be null");
     }
+
+    if (this.messenger == null) {
+        throw new IllegalStateException("The messenger instance cannot be used");
+    }
+}
 ```
 
 * When the change you are trying to make involves removing code, or delegating it somewhere else, instead of removing it, you should comment it out.

paper-server/src/main/java/org/bukkit/craftbukkit/CraftEffect.java

@@ -1,8 +1,8 @@
 package org.bukkit.craftbukkit;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.level.block.Block;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Axis;
 import org.bukkit.Color;
 import org.bukkit.Effect;
@@ -25,7 +25,7 @@ public class CraftEffect {
             datavalue = ((Color) data).asRGB();
             break;
         case RECORD_PLAY:
-            Validate.isTrue(data == Material.AIR || ((Material) data).isRecord(), "Invalid record type!");
+            Preconditions.checkArgument(data == Material.AIR || ((Material) data).isRecord(), "Invalid record type for Material %s!", data);
             datavalue = Item.getId(CraftMagicNumbers.getItem((Material) data));
             break;
         case SMOKE:
@@ -59,7 +59,7 @@ public class CraftEffect {
             }
             break;
         case STEP_SOUND:
-            Validate.isTrue(((Material) data).isBlock(), "Material is not a block!");
+            Preconditions.checkArgument(((Material) data).isBlock(), "Material %s is not a block!", data);
             datavalue = Block.getId(CraftMagicNumbers.getBlock((Material) data).defaultBlockState());
             break;
         case COMPOSTER_FILL_ATTEMPT:

paper-server/src/main/java/org/bukkit/craftbukkit/CraftIpBanList.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import java.io.IOException;
 import java.net.InetSocketAddress;
@@ -9,7 +10,6 @@ import java.util.logging.Level;
 import net.minecraft.server.players.IpBanEntry;
 import net.minecraft.server.players.IpBanList;
 import org.apache.commons.lang.StringUtils;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
 
 public class CraftIpBanList implements org.bukkit.BanList {
@@ -21,7 +21,7 @@ public class CraftIpBanList implements org.bukkit.BanList {
 
     @Override
     public org.bukkit.BanEntry getBanEntry(String target) {
-        Validate.notNull(target, "Target cannot be null");
+        Preconditions.checkArgument(target != null, "Target cannot be null");
 
         IpBanEntry entry = (IpBanEntry) list.get(target);
         if (entry == null) {
@@ -33,7 +33,7 @@ public class CraftIpBanList implements org.bukkit.BanList {
 
     @Override
     public org.bukkit.BanEntry addBan(String target, String reason, Date expires, String source) {
-        Validate.notNull(target, "Ban target cannot be null");
+        Preconditions.checkArgument(target != null, "Ban target cannot be null");
 
         IpBanEntry entry = new IpBanEntry(target, new Date(),
                 StringUtils.isBlank(source) ? null : source, expires,
@@ -62,14 +62,14 @@ public class CraftIpBanList implements org.bukkit.BanList {
 
     @Override
     public boolean isBanned(String target) {
-        Validate.notNull(target, "Target cannot be null");
+        Preconditions.checkArgument(target != null, "Target cannot be null");
 
         return list.isBanned(InetSocketAddress.createUnresolved(target, 0));
     }
 
     @Override
     public void pardon(String target) {
-        Validate.notNull(target, "Target cannot be null");
+        Preconditions.checkArgument(target != null, "Target cannot be null");
 
         list.remove(target);
     }

paper-server/src/main/java/org/bukkit/craftbukkit/CraftProfileBanList.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import com.mojang.authlib.GameProfile;
 import java.io.IOException;
@@ -12,7 +13,6 @@ import net.minecraft.server.players.GameProfileBanEntry;
 import net.minecraft.server.players.GameProfileBanList;
 import net.minecraft.server.players.JsonListEntry;
 import org.apache.commons.lang.StringUtils;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
 
 public class CraftProfileBanList implements org.bukkit.BanList {
@@ -24,7 +24,7 @@ public class CraftProfileBanList implements org.bukkit.BanList {
 
     @Override
     public org.bukkit.BanEntry getBanEntry(String target) {
-        Validate.notNull(target, "Target cannot be null");
+        Preconditions.checkArgument(target != null, "Target cannot be null");
 
         GameProfile profile = getProfile(target);
         if (profile == null) {
@@ -41,7 +41,7 @@ public class CraftProfileBanList implements org.bukkit.BanList {
 
     @Override
     public org.bukkit.BanEntry addBan(String target, String reason, Date expires, String source) {
-        Validate.notNull(target, "Ban target cannot be null");
+        Preconditions.checkArgument(target != null, "Ban target cannot be null");
 
         GameProfile profile = getProfile(target);
         if (profile == null) {
@@ -77,7 +77,7 @@ public class CraftProfileBanList implements org.bukkit.BanList {
 
     @Override
     public boolean isBanned(String target) {
-        Validate.notNull(target, "Target cannot be null");
+        Preconditions.checkArgument(target != null, "Target cannot be null");
 
         GameProfile profile = getProfile(target);
         if (profile == null) {
@@ -89,7 +89,7 @@ public class CraftProfileBanList implements org.bukkit.BanList {
 
     @Override
     public void pardon(String target) {
-        Validate.notNull(target, "Target cannot be null");
+        Preconditions.checkArgument(target != null, "Target cannot be null");
 
         GameProfile profile = getProfile(target);
         list.remove(profile);

paper-server/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java

@@ -585,9 +585,8 @@ public abstract class CraftRegionAccessor implements RegionAccessor {
 
     @SuppressWarnings("unchecked")
     public net.minecraft.world.entity.Entity createEntity(Location location, Class<? extends Entity> clazz, boolean randomizeData) throws IllegalArgumentException {
-        if (location == null || clazz == null) {
+        Preconditions.checkArgument(location != null, "Location cannot be null");
-            throw new IllegalArgumentException("Location or entity class cannot be null");
+        Preconditions.checkArgument(clazz != null, "Entity class cannot be null");
-        }
 
         net.minecraft.world.entity.Entity entity = null;
         net.minecraft.world.level.World world = getHandle().getMinecraftWorld();
@@ -798,11 +797,8 @@ public abstract class CraftRegionAccessor implements RegionAccessor {
                 entity = EntityTypes.WITHER.create(world);
             } else if (ComplexLivingEntity.class.isAssignableFrom(clazz)) {
                 if (EnderDragon.class.isAssignableFrom(clazz)) {
-                    if (isNormalWorld()) {
+                    Preconditions.checkArgument(this.isNormalWorld(), "Cannot spawn entity %s during world generation", clazz.getName());
                     entity = EntityTypes.ENDER_DRAGON.create(getHandle().getMinecraftWorld());
-                    } else {
-                        throw new IllegalArgumentException("Cannot spawn entity " + clazz.getName() + " during world generation");
-                    }
                 }
             } else if (Ambient.class.isAssignableFrom(clazz)) {
                 if (Bat.class.isAssignableFrom(clazz)) {

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java

@@ -117,7 +117,6 @@ import net.minecraft.world.level.storage.WorldNBTStorage;
 import net.minecraft.world.level.storage.loot.LootDataManager;
 import net.minecraft.world.level.validation.ContentValidationException;
 import net.minecraft.world.phys.Vec3D;
-import org.apache.commons.lang.Validate;
 import org.bukkit.BanList;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
@@ -553,7 +552,7 @@ public final class CraftServer implements Server {
     @Override
     @Deprecated
     public Player getPlayer(final String name) {
-        Validate.notNull(name, "Name cannot be null");
+        Preconditions.checkArgument(name != null, "name cannot be null");
 
         Player found = getPlayerExact(name);
         // Try for an exact match first.
@@ -579,7 +578,7 @@ public final class CraftServer implements Server {
     @Override
     @Deprecated
     public Player getPlayerExact(String name) {
-        Validate.notNull(name, "Name cannot be null");
+        Preconditions.checkArgument(name != null, "name cannot be null");
 
         EntityPlayer player = playerList.getPlayerByName(name);
         return (player != null) ? player.getBukkitEntity() : null;
@@ -587,8 +586,9 @@ public final class CraftServer implements Server {
 
     @Override
     public Player getPlayer(UUID id) {
-        EntityPlayer player = playerList.getPlayer(id);
+        Preconditions.checkArgument(id != null, "UUID id cannot be null");
 
+        EntityPlayer player = playerList.getPlayer(id);
         if (player != null) {
             return player.getBukkitEntity();
         }
@@ -604,9 +604,9 @@ public final class CraftServer implements Server {
     @Override
     @Deprecated
     public List<Player> matchPlayer(String partialName) {
-        Validate.notNull(partialName, "PartialName cannot be null");
+        Preconditions.checkArgument(partialName != null, "partialName cannot be null");
 
-        List<Player> matchedPlayers = new ArrayList<Player>();
+        List<Player> matchedPlayers = new ArrayList<>();
 
         for (Player iterPlayer : this.getOnlinePlayers()) {
             String iterPlayerName = iterPlayer.getName();
@@ -792,8 +792,8 @@ public final class CraftServer implements Server {
 
     @Override
     public int getTicksPerSpawns(SpawnCategory spawnCategory) {
-        Validate.notNull(spawnCategory, "SpawnCategory cannot be null");
+        Preconditions.checkArgument(spawnCategory != null, "SpawnCategory cannot be null");
-        Validate.isTrue(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory." + spawnCategory + " are not supported.");
+        Preconditions.checkArgument(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory.%s are not supported", spawnCategory);
         return this.configuration.getInt(CraftSpawnCategory.getConfigNameTicksPerSpawn(spawnCategory));
     }
 
@@ -844,8 +844,8 @@ public final class CraftServer implements Server {
 
     @Override
     public boolean dispatchCommand(CommandSender sender, String commandLine) {
-        Validate.notNull(sender, "Sender cannot be null");
+        Preconditions.checkArgument(sender != null, "sender cannot be null");
-        Validate.notNull(commandLine, "CommandLine cannot be null");
+        Preconditions.checkArgument(commandLine != null, "commandLine cannot be null");
 
         if (commandMap.dispatch(sender, commandLine)) {
             return true;
@@ -1027,7 +1027,7 @@ public final class CraftServer implements Server {
     @Override
     public World createWorld(WorldCreator creator) {
         Preconditions.checkState(console.getAllLevels().iterator().hasNext(), "Cannot create additional worlds on STARTUP");
-        Validate.notNull(creator, "Creator may not be null");
+        Preconditions.checkArgument(creator != null, "WorldCreator cannot be null");
 
         String name = creator.name();
         ChunkGenerator generator = creator.generator();
@@ -1039,8 +1039,8 @@ public final class CraftServer implements Server {
             return world;
         }
 
-        if ((folder.exists()) && (!folder.isDirectory())) {
+        if (folder.exists()) {
-            throw new IllegalArgumentException("File exists with the name '" + name + "' and isn't a folder");
+            Preconditions.checkArgument(folder.isDirectory(), "File (%s) exists and isn't a folder", name);
         }
 
         if (generator == null) {
@@ -1063,7 +1063,7 @@ public final class CraftServer implements Server {
                 actualDimension = WorldDimension.END;
                 break;
             default:
-                throw new IllegalArgumentException("Illegal dimension");
+                throw new IllegalArgumentException("Illegal dimension (" + creator.environment() + ")");
         }
 
         Convertable.ConversionSession worldSession;
@@ -1105,9 +1105,7 @@ public final class CraftServer implements Server {
         worlddata.setModdedInfo(console.getServerModName(), console.getModdedStatus().shouldReportAsModified());
 
         if (console.options.has("forceUpgrade")) {
-            net.minecraft.server.Main.forceUpgrade(worldSession, DataConverterRegistry.getDataFixer(), console.options.has("eraseCache"), () -> {
+            net.minecraft.server.Main.forceUpgrade(worldSession, DataConverterRegistry.getDataFixer(), console.options.has("eraseCache"), () -> true, iregistry);
-                return true;
-            }, iregistry);
         }
 
         long j = BiomeManager.obfuscateSeed(creator.seed());
@@ -1203,7 +1201,8 @@ public final class CraftServer implements Server {
 
     @Override
     public World getWorld(String name) {
-        Validate.notNull(name, "Name cannot be null");
+        Preconditions.checkArgument(name != null, "name cannot be null");
+        Preconditions.checkArgument(!name.isBlank(), "name cannot be empty");
 
         return worlds.get(name.toLowerCase(java.util.Locale.ENGLISH));
     }
@@ -1294,7 +1293,7 @@ public final class CraftServer implements Server {
 
     @Override
     public List<Recipe> getRecipesFor(ItemStack result) {
-        Validate.notNull(result, "Result cannot be null");
+        Preconditions.checkArgument(result != null, "ItemStack cannot be null");
 
         List<Recipe> results = new ArrayList<Recipe>();
         Iterator<Recipe> iter = recipeIterator();
@@ -1313,7 +1312,7 @@ public final class CraftServer implements Server {
 
     @Override
     public Recipe getRecipe(NamespacedKey recipeKey) {
-        Preconditions.checkArgument(recipeKey != null, "recipeKey == null");
+        Preconditions.checkArgument(recipeKey != null, "NamespacedKey recipeKey cannot be null");
 
         return getServer().getRecipeManager().byKey(CraftNamespacedKey.toMinecraft(recipeKey)).map(IRecipe::toBukkitRecipe).orElse(null);
     }
@@ -1344,8 +1343,8 @@ public final class CraftServer implements Server {
 
     @Override
     public ItemStack craftItem(ItemStack[] craftingMatrix, World world, Player player) {
-        Preconditions.checkArgument(world != null, "world must not be null");
+        Preconditions.checkArgument(world != null, "world cannot be null");
-        Preconditions.checkArgument(player != null, "player must not be null");
+        Preconditions.checkArgument(player != null, "player cannot be null");
 
         CraftWorld craftWorld = (CraftWorld) world;
         CraftPlayer craftPlayer = (CraftPlayer) player;
@@ -1575,7 +1574,7 @@ public final class CraftServer implements Server {
 
     @Override
     public CraftMapView createMap(World world) {
-        Validate.notNull(world, "World cannot be null");
+        Preconditions.checkArgument(world != null, "World cannot be null");
 
         net.minecraft.world.level.World minecraftWorld = ((CraftWorld) world).getHandle();
         // creates a new map at world spawn with the scale of 3, with out tracking position and unlimited tracking
@@ -1590,9 +1589,9 @@ public final class CraftServer implements Server {
 
     @Override
     public ItemStack createExplorerMap(World world, Location location, StructureType structureType, int radius, boolean findUnexplored) {
-        Validate.notNull(world, "World cannot be null");
+        Preconditions.checkArgument(world != null, "World cannot be null");
-        Validate.notNull(structureType, "StructureType cannot be null");
+        Preconditions.checkArgument(structureType != null, "StructureType cannot be null");
-        Validate.notNull(structureType.getMapIcon(), "Cannot create explorer maps for StructureType " + structureType.getName());
+        Preconditions.checkArgument(structureType.getMapIcon() != null, "Cannot create explorer maps for StructureType %s", structureType.getName());
 
         WorldServer worldServer = ((CraftWorld) world).getHandle();
         Location structureLocation = world.locateNearestStructure(location, structureType, radius, findUnexplored);
@@ -1640,8 +1639,8 @@ public final class CraftServer implements Server {
     @Override
     @Deprecated
     public OfflinePlayer getOfflinePlayer(String name) {
-        Validate.notNull(name, "Name cannot be null");
+        Preconditions.checkArgument(name != null, "name cannot be null");
-        Validate.notEmpty(name, "Name cannot be empty");
+        Preconditions.checkArgument(!name.isBlank(), "name cannot be empty");
 
         OfflinePlayer result = getPlayerExact(name);
         if (result == null) {
@@ -1663,7 +1662,7 @@ public final class CraftServer implements Server {
 
     @Override
     public OfflinePlayer getOfflinePlayer(UUID id) {
-        Validate.notNull(id, "UUID cannot be null");
+        Preconditions.checkArgument(id != null, "UUID id cannot be null");
 
         OfflinePlayer result = getPlayer(id);
         if (result == null) {
@@ -1708,14 +1707,16 @@ public final class CraftServer implements Server {
 
     @Override
     public void banIP(String address) {
-        Validate.notNull(address, "Address cannot be null.");
+        Preconditions.checkArgument(address != null, "address cannot be null");
+        Preconditions.checkArgument(!address.isBlank(), "address cannot be empty");
 
         this.getBanList(org.bukkit.BanList.Type.IP).addBan(address, null, null, null);
     }
 
     @Override
     public void unbanIP(String address) {
-        Validate.notNull(address, "Address cannot be null.");
+        Preconditions.checkArgument(address != null, "address cannot be null");
+        Preconditions.checkArgument(!address.isBlank(), "address cannot be empty");
 
         this.getBanList(org.bukkit.BanList.Type.IP).pardon(address);
     }
@@ -1733,7 +1734,7 @@ public final class CraftServer implements Server {
 
     @Override
     public BanList getBanList(BanList.Type type) {
-        Validate.notNull(type, "Type cannot be null");
+        Preconditions.checkArgument(type != null, "BanList.Type cannot be null");
 
         switch (type) {
         case IP:
@@ -1794,7 +1795,7 @@ public final class CraftServer implements Server {
 
     @Override
     public void setDefaultGameMode(GameMode mode) {
-        Validate.notNull(mode, "Mode cannot be null");
+        Preconditions.checkArgument(mode != null, "GameMode cannot be null");
 
         for (World world : getWorlds()) {
             ((CraftWorld) world).getHandle().serverLevelData.setGameType(EnumGamemode.byId(mode.getValue()));
@@ -1869,25 +1870,28 @@ public final class CraftServer implements Server {
 
     @Override
     public Inventory createInventory(InventoryHolder owner, InventoryType type) {
-        Validate.isTrue(type.isCreatable(), "Cannot open an inventory of type ", type);
+        Preconditions.checkArgument(type != null, "InventoryType cannot be null");
+        Preconditions.checkArgument(type.isCreatable(), "InventoryType.%s cannot be used to create a inventory", type);
         return CraftInventoryCreator.INSTANCE.createInventory(owner, type);
     }
 
     @Override
     public Inventory createInventory(InventoryHolder owner, InventoryType type, String title) {
-        Validate.isTrue(type.isCreatable(), "Cannot open an inventory of type ", type);
+        Preconditions.checkArgument(type != null, "InventoryType cannot be null");
+        Preconditions.checkArgument(type.isCreatable(), "InventoryType.%s cannot be used to create a inventory", type);
+        Preconditions.checkArgument(title != null, "title cannot be null");
         return CraftInventoryCreator.INSTANCE.createInventory(owner, type, title);
     }
 
     @Override
     public Inventory createInventory(InventoryHolder owner, int size) throws IllegalArgumentException {
-        Validate.isTrue(9 <= size && size <= 54 && size % 9 == 0, "Size for custom inventory must be a multiple of 9 between 9 and 54 slots (got " + size + ")");
+        Preconditions.checkArgument(9 <= size && size <= 54 && size % 9 == 0, "Size for custom inventory must be a multiple of 9 between 9 and 54 slots (got %s)", size);
         return CraftInventoryCreator.INSTANCE.createInventory(owner, size);
     }
 
     @Override
     public Inventory createInventory(InventoryHolder owner, int size, String title) throws IllegalArgumentException {
-        Validate.isTrue(9 <= size && size <= 54 && size % 9 == 0, "Size for custom inventory must be a multiple of 9 between 9 and 54 slots (got " + size + ")");
+        Preconditions.checkArgument(9 <= size && size <= 54 && size % 9 == 0, "Size for custom inventory must be a multiple of 9 between 9 and 54 slots (got %s)", size);
         return CraftInventoryCreator.INSTANCE.createInventory(owner, size, title);
     }
 
@@ -2063,10 +2067,8 @@ public final class CraftServer implements Server {
 
     @Override
     public CraftIconCache loadServerIcon(File file) throws Exception {
-        Validate.notNull(file, "File cannot be null");
+        Preconditions.checkArgument(file != null, "File cannot be null");
-        if (!file.isFile()) {
+        Preconditions.checkArgument(file.isFile(), "File (%s) is not a valid file", file);
-            throw new IllegalArgumentException(file + " is not a file");
-        }
         return loadServerIcon0(file);
     }
 
@@ -2076,13 +2078,13 @@ public final class CraftServer implements Server {
 
     @Override
     public CraftIconCache loadServerIcon(BufferedImage image) throws Exception {
-        Validate.notNull(image, "Image cannot be null");
+        Preconditions.checkArgument(image != null, "BufferedImage image cannot be null");
         return loadServerIcon0(image);
     }
 
     static CraftIconCache loadServerIcon0(BufferedImage image) throws Exception {
-        Validate.isTrue(image.getWidth() == 64, "Must be 64 pixels wide");
+        Preconditions.checkArgument(image.getWidth() == 64, "BufferedImage must be 64 pixels wide (%s)", image.getWidth());
-        Validate.isTrue(image.getHeight() == 64, "Must be 64 pixels high");
+        Preconditions.checkArgument(image.getHeight() == 64, "BufferedImage must be 64 pixels high (%s)", image.getHeight());
 
         ByteArrayOutputStream bytebuf = new ByteArrayOutputStream();
         ImageIO.write(image, "PNG", bytebuf);
@@ -2102,7 +2104,7 @@ public final class CraftServer implements Server {
 
     @Override
     public ChunkGenerator.ChunkData createChunkData(World world) {
-        Validate.notNull(world, "World cannot be null");
+        Preconditions.checkArgument(world != null, "World cannot be null");
         WorldServer handle = ((CraftWorld) world).getHandle();
         return new OldCraftChunkData(world.getMinHeight(), world.getMaxHeight(), handle.registryAccess().registryOrThrow(Registries.BIOME));
     }
@@ -2114,13 +2116,18 @@ public final class CraftServer implements Server {
 
     @Override
     public KeyedBossBar createBossBar(NamespacedKey key, String title, BarColor barColor, BarStyle barStyle, BarFlag... barFlags) {
-        Preconditions.checkArgument(key != null, "key");
+        Preconditions.checkArgument(key != null, "NamespacedKey key cannot be null");
+        Preconditions.checkArgument(barColor != null, "BarColor key cannot be null");
+        Preconditions.checkArgument(barStyle != null, "BarStyle key cannot be null");
 
         BossBattleCustom bossBattleCustom = getServer().getCustomBossEvents().create(CraftNamespacedKey.toMinecraft(key), CraftChatMessage.fromString(title, true)[0]);
         CraftKeyedBossbar craftKeyedBossbar = new CraftKeyedBossbar(bossBattleCustom);
         craftKeyedBossbar.setColor(barColor);
         craftKeyedBossbar.setStyle(barStyle);
         for (BarFlag flag : barFlags) {
+            if (flag == null) {
+                continue;
+            }
             craftKeyedBossbar.addFlag(flag);
         }
 
@@ -2161,7 +2168,7 @@ public final class CraftServer implements Server {
 
     @Override
     public Entity getEntity(UUID uuid) {
-        Validate.notNull(uuid, "UUID cannot be null");
+        Preconditions.checkArgument(uuid != null, "UUID id cannot be null");
 
         for (WorldServer world : getServer().getAllLevels()) {
             net.minecraft.world.entity.Entity entity = world.getEntity(uuid);
@@ -2175,7 +2182,7 @@ public final class CraftServer implements Server {
 
     @Override
     public org.bukkit.advancement.Advancement getAdvancement(NamespacedKey key) {
-        Preconditions.checkArgument(key != null, "key");
+        Preconditions.checkArgument(key != null, "NamespacedKey key cannot be null");
 
         Advancement advancement = console.getAdvancements().getAdvancement(CraftNamespacedKey.toMinecraft(key));
         return (advancement == null) ? null : advancement.bukkit;
@@ -2193,7 +2200,7 @@ public final class CraftServer implements Server {
 
     @Override
     public BlockData createBlockData(org.bukkit.Material material) {
-        Validate.isTrue(material != null, "Must provide material");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
 
         return createBlockData(material, (String) null);
     }
@@ -2211,14 +2218,14 @@ public final class CraftServer implements Server {
 
     @Override
     public BlockData createBlockData(String data) throws IllegalArgumentException {
-        Validate.isTrue(data != null, "Must provide data");
+        Preconditions.checkArgument(data != null, "data cannot be null");
 
         return createBlockData(null, data);
     }
 
     @Override
     public BlockData createBlockData(org.bukkit.Material material, String data) {
-        Validate.isTrue(material != null || data != null, "Must provide one of material or data");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
 
         return CraftBlockData.newData(material, data);
     }
@@ -2226,35 +2233,35 @@ public final class CraftServer implements Server {
     @Override
     @SuppressWarnings("unchecked")
     public <T extends Keyed> org.bukkit.Tag<T> getTag(String registry, NamespacedKey tag, Class<T> clazz) {
-        Validate.notNull(registry, "registry cannot be null");
+        Preconditions.checkArgument(registry != null, "registry cannot be null");
-        Validate.notNull(tag, "NamespacedKey cannot be null");
+        Preconditions.checkArgument(tag != null, "NamespacedKey tag cannot be null");
-        Validate.notNull(clazz, "Class cannot be null");
+        Preconditions.checkArgument(clazz != null, "Class clazz cannot be null");
         MinecraftKey key = CraftNamespacedKey.toMinecraft(tag);
 
         switch (registry) {
             case org.bukkit.Tag.REGISTRY_BLOCKS -> {
-                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Block namespace must have material type");
+                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Block namespace (%s) must have material type", clazz.getName());
                 TagKey<Block> blockTagKey = TagKey.create(Registries.BLOCK, key);
                 if (BuiltInRegistries.BLOCK.getTag(blockTagKey).isPresent()) {
                     return (org.bukkit.Tag<T>) new CraftBlockTag(BuiltInRegistries.BLOCK, blockTagKey);
                 }
             }
             case org.bukkit.Tag.REGISTRY_ITEMS -> {
-                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Item namespace must have material type");
+                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Item namespace (%s) must have material type", clazz.getName());
                 TagKey<Item> itemTagKey = TagKey.create(Registries.ITEM, key);
                 if (BuiltInRegistries.ITEM.getTag(itemTagKey).isPresent()) {
                     return (org.bukkit.Tag<T>) new CraftItemTag(BuiltInRegistries.ITEM, itemTagKey);
                 }
             }
             case org.bukkit.Tag.REGISTRY_FLUIDS -> {
-                Preconditions.checkArgument(clazz == org.bukkit.Fluid.class, "Fluid namespace must have fluid type");
+                Preconditions.checkArgument(clazz == org.bukkit.Fluid.class, "Fluid namespace (%s) must have fluid type", clazz.getName());
                 TagKey<FluidType> fluidTagKey = TagKey.create(Registries.FLUID, key);
                 if (BuiltInRegistries.FLUID.getTag(fluidTagKey).isPresent()) {
                     return (org.bukkit.Tag<T>) new CraftFluidTag(BuiltInRegistries.FLUID, fluidTagKey);
                 }
             }
             case org.bukkit.Tag.REGISTRY_ENTITY_TYPES -> {
-                Preconditions.checkArgument(clazz == org.bukkit.entity.EntityType.class, "Entity type namespace must have entity type");
+                Preconditions.checkArgument(clazz == org.bukkit.entity.EntityType.class, "Entity type namespace (%s) must have entity type", clazz.getName());
                 TagKey<EntityTypes<?>> entityTagKey = TagKey.create(Registries.ENTITY_TYPE, key);
                 if (BuiltInRegistries.ENTITY_TYPE.getTag(entityTagKey).isPresent()) {
                     return (org.bukkit.Tag<T>) new CraftEntityTag(BuiltInRegistries.ENTITY_TYPE, entityTagKey);
@@ -2269,26 +2276,26 @@ public final class CraftServer implements Server {
     @Override
     @SuppressWarnings("unchecked")
     public <T extends Keyed> Iterable<org.bukkit.Tag<T>> getTags(String registry, Class<T> clazz) {
-        Validate.notNull(registry, "registry cannot be null");
+        Preconditions.checkArgument(registry != null, "registry cannot be null");
-        Validate.notNull(clazz, "Class cannot be null");
+        Preconditions.checkArgument(clazz != null, "Class clazz cannot be null");
         switch (registry) {
             case org.bukkit.Tag.REGISTRY_BLOCKS -> {
-                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Block namespace must have material type");
+                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Block namespace (%s) must have material type", clazz.getName());
                 IRegistry<Block> blockTags = BuiltInRegistries.BLOCK;
                 return blockTags.getTags().map(pair -> (org.bukkit.Tag<T>) new CraftBlockTag(blockTags, pair.getFirst())).collect(ImmutableList.toImmutableList());
             }
             case org.bukkit.Tag.REGISTRY_ITEMS -> {
-                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Item namespace must have material type");
+                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Item namespace (%s) must have material type", clazz.getName());
                 IRegistry<Item> itemTags = BuiltInRegistries.ITEM;
                 return itemTags.getTags().map(pair -> (org.bukkit.Tag<T>) new CraftItemTag(itemTags, pair.getFirst())).collect(ImmutableList.toImmutableList());
             }
             case org.bukkit.Tag.REGISTRY_FLUIDS -> {
-                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Fluid namespace must have fluid type");
+                Preconditions.checkArgument(clazz == org.bukkit.Material.class, "Fluid namespace (%s) must have fluid type", clazz.getName());
                 IRegistry<FluidType> fluidTags = BuiltInRegistries.FLUID;
                 return fluidTags.getTags().map(pair -> (org.bukkit.Tag<T>) new CraftFluidTag(fluidTags, pair.getFirst())).collect(ImmutableList.toImmutableList());
             }
             case org.bukkit.Tag.REGISTRY_ENTITY_TYPES -> {
-                Preconditions.checkArgument(clazz == org.bukkit.entity.EntityType.class, "Entity type namespace must have entity type");
+                Preconditions.checkArgument(clazz == org.bukkit.entity.EntityType.class, "Entity type namespace (%s) must have entity type", clazz.getName());
                 IRegistry<EntityTypes<?>> entityTags = BuiltInRegistries.ENTITY_TYPE;
                 return entityTags.getTags().map(pair -> (org.bukkit.Tag<T>) new CraftEntityTag(entityTags, pair.getFirst())).collect(ImmutableList.toImmutableList());
             }
@@ -2298,7 +2305,7 @@ public final class CraftServer implements Server {
 
     @Override
     public LootTable getLootTable(NamespacedKey key) {
-        Validate.notNull(key, "NamespacedKey cannot be null");
+        Preconditions.checkArgument(key != null, "NamespacedKey key cannot be null");
 
         LootDataManager registry = getServer().getLootData();
         return new CraftLootTable(key, registry.getLootTable(CraftNamespacedKey.toMinecraft(key)));
@@ -2306,8 +2313,8 @@ public final class CraftServer implements Server {
 
     @Override
     public List<Entity> selectEntities(CommandSender sender, String selector) {
-        Preconditions.checkArgument(selector != null, "Selector cannot be null");
+        Preconditions.checkArgument(selector != null, "selector cannot be null");
-        Preconditions.checkArgument(sender != null, "Sender cannot be null");
+        Preconditions.checkArgument(sender != null, "CommandSender sender cannot be null");
 
         ArgumentEntity arg = ArgumentEntity.entities();
         List<? extends net.minecraft.world.entity.Entity> nms;
@@ -2315,7 +2322,7 @@ public final class CraftServer implements Server {
         try {
             StringReader reader = new StringReader(selector);
             nms = arg.parse(reader, true).findEntities(VanillaCommandWrapper.getListener(sender));
-            Preconditions.checkArgument(!reader.canRead(), "Spurious trailing data in selector: " + selector);
+            Preconditions.checkArgument(!reader.canRead(), "Spurious trailing data in selector: %s", selector);
         } catch (CommandSyntaxException ex) {
             throw new IllegalArgumentException("Could not parse selector: " + selector, ex);
         }

paper-server/src/main/java/org/bukkit/craftbukkit/CraftStatistic.java

@@ -11,7 +11,6 @@ import net.minecraft.stats.StatisticList;
 import net.minecraft.world.entity.EntityTypes;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.level.block.Block;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.Statistic;
 import org.bukkit.Statistic.Type;
@@ -123,6 +122,7 @@ public enum CraftStatistic {
     }
 
     public static org.bukkit.Statistic getBukkitStatistic(net.minecraft.stats.Statistic<?> statistic) {
+        Preconditions.checkArgument(statistic != null, "NMS Statistic cannot be null");
         IRegistry statRegistry = statistic.getType().getRegistry();
         MinecraftKey nmsKey = BuiltInRegistries.STAT_TYPE.getKey(statistic.getType());
 
@@ -169,6 +169,7 @@ public enum CraftStatistic {
     }
 
     public static net.minecraft.stats.Statistic getEntityStatistic(org.bukkit.Statistic stat, EntityType entity) {
+        Preconditions.checkArgument(entity != null, "EntityType cannot be null");
         if (entity.getName() != null) {
             EntityTypes<?> nmsEntity = BuiltInRegistries.ENTITY_TYPE.get(new MinecraftKey(entity.getName()));
 
@@ -183,16 +184,17 @@ public enum CraftStatistic {
     }
 
     public static EntityType getEntityTypeFromStatistic(net.minecraft.stats.Statistic<EntityTypes<?>> statistic) {
+        Preconditions.checkArgument(statistic != null, "NMS Statistic cannot be null");
         MinecraftKey name = EntityTypes.getKey(statistic.getValue());
         return EntityType.fromName(name.getPath());
     }
 
     public static Material getMaterialFromStatistic(net.minecraft.stats.Statistic<?> statistic) {
-        if (statistic.getValue() instanceof Item) {
+        if (statistic.getValue() instanceof Item statisticItemValue) {
-            return CraftMagicNumbers.getMaterial((Item) statistic.getValue());
+            return CraftMagicNumbers.getMaterial(statisticItemValue);
         }
-        if (statistic.getValue() instanceof Block) {
+        if (statistic.getValue() instanceof Block statisticBlockValue) {
-            return CraftMagicNumbers.getMaterial((Block) statistic.getValue());
+            return CraftMagicNumbers.getMaterial(statisticBlockValue);
         }
         return null;
     }
@@ -206,25 +208,25 @@ public enum CraftStatistic {
     }
 
     public static int getStatistic(ServerStatisticManager manager, Statistic statistic) {
-        Validate.notNull(statistic, "Statistic cannot be null");
+        Preconditions.checkArgument(statistic != null, "Statistic cannot be null");
-        Validate.isTrue(statistic.getType() == Type.UNTYPED, "Must supply additional paramater for this statistic");
+        Preconditions.checkArgument(statistic.getType() == Type.UNTYPED, "Must supply additional parameter for this statistic");
         return manager.getValue(CraftStatistic.getNMSStatistic(statistic));
     }
 
     public static void incrementStatistic(ServerStatisticManager manager, Statistic statistic, int amount) {
-        Validate.isTrue(amount > 0, "Amount must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Amount must be greater than 0");
         setStatistic(manager, statistic, getStatistic(manager, statistic) + amount);
     }
 
     public static void decrementStatistic(ServerStatisticManager manager, Statistic statistic, int amount) {
-        Validate.isTrue(amount > 0, "Amount must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Amount must be greater than 0");
         setStatistic(manager, statistic, getStatistic(manager, statistic) - amount);
     }
 
     public static void setStatistic(ServerStatisticManager manager, Statistic statistic, int newValue) {
-        Validate.notNull(statistic, "Statistic cannot be null");
+        Preconditions.checkArgument(statistic != null, "Statistic cannot be null");
-        Validate.isTrue(statistic.getType() == Type.UNTYPED, "Must supply additional paramater for this statistic");
+        Preconditions.checkArgument(statistic.getType() == Type.UNTYPED, "Must supply additional parameter for this statistic");
-        Validate.isTrue(newValue >= 0, "Value must be greater than or equal to 0");
+        Preconditions.checkArgument(newValue >= 0, "Value must be greater than or equal to 0");
         net.minecraft.stats.Statistic nmsStatistic = CraftStatistic.getNMSStatistic(statistic);
         manager.setValue(null, nmsStatistic, newValue);;
     }
@@ -238,31 +240,31 @@ public enum CraftStatistic {
     }
 
     public static int getStatistic(ServerStatisticManager manager, Statistic statistic, Material material) {
-        Validate.notNull(statistic, "Statistic cannot be null");
+        Preconditions.checkArgument(statistic != null, "Statistic cannot be null");
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
-        Validate.isTrue(statistic.getType() == Type.BLOCK || statistic.getType() == Type.ITEM, "This statistic does not take a Material parameter");
+        Preconditions.checkArgument(statistic.getType() == Type.BLOCK || statistic.getType() == Type.ITEM, "This statistic does not take a Material parameter");
         net.minecraft.stats.Statistic nmsStatistic = CraftStatistic.getMaterialStatistic(statistic, material);
-        Validate.notNull(nmsStatistic, "The supplied Material does not have a corresponding statistic");
+        Preconditions.checkArgument(nmsStatistic != null, "The supplied Material %s does not have a corresponding statistic", material);
         return manager.getValue(nmsStatistic);
     }
 
     public static void incrementStatistic(ServerStatisticManager manager, Statistic statistic, Material material, int amount) {
-        Validate.isTrue(amount > 0, "Amount must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Amount must be greater than 0");
         setStatistic(manager, statistic, material, getStatistic(manager, statistic, material) + amount);
     }
 
     public static void decrementStatistic(ServerStatisticManager manager, Statistic statistic, Material material, int amount) {
-        Validate.isTrue(amount > 0, "Amount must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Amount must be greater than 0");
         setStatistic(manager, statistic, material, getStatistic(manager, statistic, material) - amount);
     }
 
     public static void setStatistic(ServerStatisticManager manager, Statistic statistic, Material material, int newValue) {
-        Validate.notNull(statistic, "Statistic cannot be null");
+        Preconditions.checkArgument(statistic != null, "Statistic cannot be null");
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
-        Validate.isTrue(newValue >= 0, "Value must be greater than or equal to 0");
+        Preconditions.checkArgument(newValue >= 0, "Value must be greater than or equal to 0");
-        Validate.isTrue(statistic.getType() == Type.BLOCK || statistic.getType() == Type.ITEM, "This statistic does not take a Material parameter");
+        Preconditions.checkArgument(statistic.getType() == Type.BLOCK || statistic.getType() == Type.ITEM, "This statistic does not take a Material parameter");
         net.minecraft.stats.Statistic nmsStatistic = CraftStatistic.getMaterialStatistic(statistic, material);
-        Validate.notNull(nmsStatistic, "The supplied Material does not have a corresponding statistic");
+        Preconditions.checkArgument(nmsStatistic != null, "The supplied Material %s does not have a corresponding statistic", material);
         manager.setValue(null, nmsStatistic, newValue);
     }
 
@@ -275,31 +277,31 @@ public enum CraftStatistic {
     }
 
     public static int getStatistic(ServerStatisticManager manager, Statistic statistic, EntityType entityType) {
-        Validate.notNull(statistic, "Statistic cannot be null");
+        Preconditions.checkArgument(statistic != null, "Statistic cannot be null");
-        Validate.notNull(entityType, "EntityType cannot be null");
+        Preconditions.checkArgument(entityType != null, "EntityType cannot be null");
-        Validate.isTrue(statistic.getType() == Type.ENTITY, "This statistic does not take an EntityType parameter");
+        Preconditions.checkArgument(statistic.getType() == Type.ENTITY, "This statistic does not take an EntityType parameter");
         net.minecraft.stats.Statistic nmsStatistic = CraftStatistic.getEntityStatistic(statistic, entityType);
-        Validate.notNull(nmsStatistic, "The supplied EntityType does not have a corresponding statistic");
+        Preconditions.checkArgument(nmsStatistic != null, "The supplied EntityType %s does not have a corresponding statistic", entityType);
         return manager.getValue(nmsStatistic);
     }
 
     public static void incrementStatistic(ServerStatisticManager manager, Statistic statistic, EntityType entityType, int amount) {
-        Validate.isTrue(amount > 0, "Amount must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Amount must be greater than 0");
         setStatistic(manager, statistic, entityType, getStatistic(manager, statistic, entityType) + amount);
     }
 
     public static void decrementStatistic(ServerStatisticManager manager, Statistic statistic, EntityType entityType, int amount) {
-        Validate.isTrue(amount > 0, "Amount must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Amount must be greater than 0");
         setStatistic(manager, statistic, entityType, getStatistic(manager, statistic, entityType) - amount);
     }
 
     public static void setStatistic(ServerStatisticManager manager, Statistic statistic, EntityType entityType, int newValue) {
-        Validate.notNull(statistic, "Statistic cannot be null");
+        Preconditions.checkArgument(statistic != null, "Statistic cannot be null");
-        Validate.notNull(entityType, "EntityType cannot be null");
+        Preconditions.checkArgument(entityType != null, "EntityType cannot be null");
-        Validate.isTrue(newValue >= 0, "Value must be greater than or equal to 0");
+        Preconditions.checkArgument(newValue >= 0, "Value must be greater than or equal to 0");
-        Validate.isTrue(statistic.getType() == Type.ENTITY, "This statistic does not take an EntityType parameter");
+        Preconditions.checkArgument(statistic.getType() == Type.ENTITY, "This statistic does not take an EntityType parameter");
         net.minecraft.stats.Statistic nmsStatistic = CraftStatistic.getEntityStatistic(statistic, entityType);
-        Validate.notNull(nmsStatistic, "The supplied EntityType does not have a corresponding statistic");
+        Preconditions.checkArgument(nmsStatistic != null, "The supplied EntityType %s does not have a corresponding statistic", entityType);
         manager.setValue(null, nmsStatistic, newValue);
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -67,7 +67,6 @@ import net.minecraft.world.level.storage.SavedFile;
 import net.minecraft.world.phys.AxisAlignedBB;
 import net.minecraft.world.phys.MovingObjectPosition;
 import net.minecraft.world.phys.Vec3D;
-import org.apache.commons.lang.Validate;
 import org.bukkit.BlockChangeDelegate;
 import org.bukkit.Bukkit;
 import org.bukkit.Chunk;
@@ -486,14 +485,17 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public org.bukkit.entity.Item dropItem(Location loc, ItemStack item, Consumer<org.bukkit.entity.Item> function) {
-        Validate.notNull(item, "Cannot drop a Null item.");
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+        Preconditions.checkArgument(item != null, "ItemStack cannot be null");
+
         EntityItem entity = new EntityItem(world, loc.getX(), loc.getY(), loc.getZ(), CraftItemStack.asNMSCopy(item));
+        org.bukkit.entity.Item itemEntity = (org.bukkit.entity.Item) entity.getBukkitEntity();
         entity.pickupDelay = 10;
         if (function != null) {
-            function.accept((org.bukkit.entity.Item) entity.getBukkitEntity());
+            function.accept(itemEntity);
         }
         world.addFreshEntity(entity, SpawnReason.CUSTOM);
-        return (org.bukkit.entity.Item) entity.getBukkitEntity();
+        return itemEntity;
     }
 
     @Override
@@ -503,13 +505,13 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public org.bukkit.entity.Item dropItemNaturally(Location loc, ItemStack item, Consumer<org.bukkit.entity.Item> function) {
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+        Preconditions.checkArgument(item != null, "ItemStack cannot be null");
+
         double xs = (world.random.nextFloat() * 0.5F) + 0.25D;
         double ys = (world.random.nextFloat() * 0.5F) + 0.25D;
         double zs = (world.random.nextFloat() * 0.5F) + 0.25D;
-        loc = loc.clone();
+        loc = loc.clone().add(xs, ys, zs);
-        loc.setX(loc.getX() + xs);
-        loc.setY(loc.getY() + ys);
-        loc.setZ(loc.getZ() + zs);
         return dropItem(loc, item, function);
     }
 
@@ -520,9 +522,9 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public <T extends AbstractArrow> T spawnArrow(Location loc, Vector velocity, float speed, float spread, Class<T> clazz) {
-        Validate.notNull(loc, "Can not spawn arrow with a null location");
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
-        Validate.notNull(velocity, "Can not spawn arrow with a null velocity");
+        Preconditions.checkArgument(velocity != null, "Vector cannot be null");
-        Validate.notNull(clazz, "Can not spawn an arrow with no class");
+        Preconditions.checkArgument(clazz != null, "clazz Entity for the arrow cannot be null");
 
         EntityArrow arrow;
         if (TippedArrow.class.isAssignableFrom(clazz)) {
@@ -544,17 +546,20 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public LightningStrike strikeLightning(Location loc) {
-        EntityLightning lightning = EntityTypes.LIGHTNING_BOLT.create(world);
+        return strikeLightning0(loc, false);
-        lightning.moveTo(loc.getX(), loc.getY(), loc.getZ());
-        world.strikeLightning(lightning, LightningStrikeEvent.Cause.CUSTOM);
-        return (LightningStrike) lightning.getBukkitEntity();
     }
 
     @Override
     public LightningStrike strikeLightningEffect(Location loc) {
+        return strikeLightning0(loc, true);
+    }
+
+    private LightningStrike strikeLightning0(Location loc, boolean isVisual) {
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+
         EntityLightning lightning = EntityTypes.LIGHTNING_BOLT.create(world);
         lightning.moveTo(loc.getX(), loc.getY(), loc.getZ());
-        lightning.setVisualOnly(true);
+        lightning.setVisualOnly(isVisual);
         world.strikeLightning(lightning, LightningStrikeEvent.Cause.CUSTOM);
         return (LightningStrike) lightning.getBukkitEntity();
     }
@@ -822,8 +827,8 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public Collection<Entity> getNearbyEntities(Location location, double x, double y, double z, Predicate<Entity> filter) {
-        Validate.notNull(location, "Location is null!");
+        Preconditions.checkArgument(location != null, "Location cannot be null");
-        Validate.isTrue(this.equals(location.getWorld()), "Location is from different world!");
+        Preconditions.checkArgument(this.equals(location.getWorld()), "Location cannot be in a different world");
 
         BoundingBox aabb = BoundingBox.of(location, x, y, z);
         return this.getNearbyEntities(aabb, filter);
@@ -836,7 +841,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public Collection<Entity> getNearbyEntities(BoundingBox boundingBox, Predicate<Entity> filter) {
-        Validate.notNull(boundingBox, "Bounding box is null!");
+        Preconditions.checkArgument(boundingBox != null, "BoundingBox cannot be null");
 
         AxisAlignedBB bb = new AxisAlignedBB(boundingBox.getMinX(), boundingBox.getMinY(), boundingBox.getMinZ(), boundingBox.getMaxX(), boundingBox.getMaxY(), boundingBox.getMaxZ());
         List<net.minecraft.world.entity.Entity> entityList = getHandle().getEntities((net.minecraft.world.entity.Entity) null, bb, Predicates.alwaysTrue());
@@ -869,14 +874,14 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public RayTraceResult rayTraceEntities(Location start, Vector direction, double maxDistance, double raySize, Predicate<Entity> filter) {
-        Validate.notNull(start, "Start location is null!");
+        Preconditions.checkArgument(start != null, "Location start cannot be null");
-        Validate.isTrue(this.equals(start.getWorld()), "Start location is from different world!");
+        Preconditions.checkArgument(this.equals(start.getWorld()), "Location start cannot be in a different world");
         start.checkFinite();
 
-        Validate.notNull(direction, "Direction is null!");
+        Preconditions.checkArgument(direction != null, "Vector direction cannot be null");
         direction.checkFinite();
 
-        Validate.isTrue(direction.lengthSquared() > 0, "Direction's magnitude is 0!");
+        Preconditions.checkArgument(direction.lengthSquared() > 0, "Direction's magnitude (%s) need to be greater than 0", direction.lengthSquared());
 
         if (maxDistance < 0.0D) {
             return null;
@@ -921,15 +926,15 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public RayTraceResult rayTraceBlocks(Location start, Vector direction, double maxDistance, FluidCollisionMode fluidCollisionMode, boolean ignorePassableBlocks) {
-        Validate.notNull(start, "Start location is null!");
+        Preconditions.checkArgument(start != null, "Location start cannot be null");
-        Validate.isTrue(this.equals(start.getWorld()), "Start location is from different world!");
+        Preconditions.checkArgument(this.equals(start.getWorld()), "Location start cannot be in a different world");
         start.checkFinite();
 
-        Validate.notNull(direction, "Direction is null!");
+        Preconditions.checkArgument(direction != null, "Vector direction cannot be null");
         direction.checkFinite();
 
-        Validate.isTrue(direction.lengthSquared() > 0, "Direction's magnitude is 0!");
+        Preconditions.checkArgument(direction.lengthSquared() > 0, "Direction's magnitude (%s) need to be greater than 0", direction.lengthSquared());
-        Validate.notNull(fluidCollisionMode, "Fluid collision mode is null!");
+        Preconditions.checkArgument(fluidCollisionMode != null, "FluidCollisionMode cannot be null");
 
         if (maxDistance < 0.0D) {
             return null;
@@ -1114,10 +1119,11 @@ public class CraftWorld extends CraftRegionAccessor implements World {
     @Override
     public <T> void playEffect(Location loc, Effect effect, T data, int radius) {
         if (data != null) {
-            Validate.isTrue(effect.getData() != null && effect.getData().isAssignableFrom(data.getClass()), "Wrong kind of data for this effect!");
+            Preconditions.checkArgument(effect.getData() != null, "Effect.%s does not have a valid Data", effect);
+            Preconditions.checkArgument(effect.getData().isAssignableFrom(data.getClass()), "%s data cannot be used for the %s effect", data.getClass().getName(), effect);
         } else {
             // Special case: the axis is optional for ELECTRIC_SPARK
-            Validate.isTrue(effect.getData() == null || effect == Effect.ELECTRIC_SPARK, "Wrong kind of data for this effect!");
+            Preconditions.checkArgument(effect.getData() == null || effect == Effect.ELECTRIC_SPARK, "Wrong kind of data for the %s effect", effect);
         }
 
         int datavalue = CraftEffect.getDataValue(effect, data);
@@ -1126,9 +1132,9 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void playEffect(Location location, Effect effect, int data, int radius) {
-        Validate.notNull(location, "Location cannot be null");
+        Preconditions.checkArgument(effect != null, "Effect cannot be null");
-        Validate.notNull(effect, "Effect cannot be null");
+        Preconditions.checkArgument(location != null, "Location cannot be null");
-        Validate.notNull(location.getWorld(), "World cannot be null");
+        Preconditions.checkArgument(location.getWorld() != null, "World of Location cannot be null");
         int packetData = effect.getId();
         PacketPlayOutWorldEvent packet = new PacketPlayOutWorldEvent(packetData, CraftLocation.toBlockPosition(location), data, false);
         int distance;
@@ -1147,15 +1153,15 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public FallingBlock spawnFallingBlock(Location location, MaterialData data) throws IllegalArgumentException {
-        Validate.notNull(data, "MaterialData cannot be null");
+        Preconditions.checkArgument(data != null, "MaterialData cannot be null");
         return spawnFallingBlock(location, data.getItemType(), data.getData());
     }
 
     @Override
     public FallingBlock spawnFallingBlock(Location location, org.bukkit.Material material, byte data) throws IllegalArgumentException {
-        Validate.notNull(location, "Location cannot be null");
+        Preconditions.checkArgument(location != null, "Location cannot be null");
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
-        Validate.isTrue(material.isBlock(), "Material must be a block");
+        Preconditions.checkArgument(material.isBlock(), "Material.%s must be a block", material);
 
         EntityFallingBlock entity = EntityFallingBlock.fall(world, BlockPosition.containing(location.getX(), location.getY(), location.getZ()), CraftMagicNumbers.getBlock(material).defaultBlockState(), SpawnReason.CUSTOM);
         return (FallingBlock) entity.getBukkitEntity();
@@ -1163,8 +1169,8 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public FallingBlock spawnFallingBlock(Location location, BlockData data) throws IllegalArgumentException {
-        Validate.notNull(location, "Location cannot be null");
+        Preconditions.checkArgument(location != null, "Location cannot be null");
-        Validate.notNull(data, "BlockData cannot be null");
+        Preconditions.checkArgument(data != null, "BlockData cannot be null");
 
         EntityFallingBlock entity = EntityFallingBlock.fall(world, BlockPosition.containing(location.getX(), location.getY(), location.getZ()), ((CraftBlockData) data).getState(), SpawnReason.CUSTOM);
         return (FallingBlock) entity.getBukkitEntity();
@@ -1406,16 +1412,16 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void setTicksPerSpawns(SpawnCategory spawnCategory, int ticksPerCategorySpawn) {
-        Validate.notNull(spawnCategory, "SpawnCategory cannot be null");
+        Preconditions.checkArgument(spawnCategory != null, "SpawnCategory cannot be null");
-        Validate.isTrue(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory." + spawnCategory + " are not supported.");
+        Preconditions.checkArgument(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory.%s are not supported", spawnCategory);
 
         world.ticksPerSpawnCategory.put(spawnCategory, (long) ticksPerCategorySpawn);
     }
 
     @Override
     public long getTicksPerSpawns(SpawnCategory spawnCategory) {
-        Validate.notNull(spawnCategory, "SpawnCategory cannot be null");
+        Preconditions.checkArgument(spawnCategory != null, "SpawnCategory cannot be null");
-        Validate.isTrue(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory." + spawnCategory + " are not supported.");
+        Preconditions.checkArgument(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory.%s are not supported", spawnCategory);
 
         return world.ticksPerSpawnCategory.getLong(spawnCategory);
     }
@@ -1514,8 +1520,8 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public int getSpawnLimit(SpawnCategory spawnCategory) {
-        Validate.notNull(spawnCategory, "SpawnCategory cannot be null");
+        Preconditions.checkArgument(spawnCategory != null, "SpawnCategory cannot be null");
-        Validate.isTrue(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory." + spawnCategory + " are not supported.");
+        Preconditions.checkArgument(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory.%s are not supported", spawnCategory);
 
         int limit = spawnCategoryLimit.getOrDefault(spawnCategory, -1);
         if (limit < 0) {
@@ -1526,8 +1532,8 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void setSpawnLimit(SpawnCategory spawnCategory, int limit) {
-        Validate.notNull(spawnCategory, "SpawnCategory cannot be null");
+        Preconditions.checkArgument(spawnCategory != null, "SpawnCategory cannot be null");
-        Validate.isTrue(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory." + spawnCategory + " are not supported.");
+        Preconditions.checkArgument(CraftSpawnCategory.isValidForLimits(spawnCategory), "SpawnCategory.%s are not supported", spawnCategory);
 
         spawnCategoryLimit.put(spawnCategory, limit);
     }
@@ -1544,7 +1550,9 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void playSound(Location loc, Sound sound, org.bukkit.SoundCategory category, float volume, float pitch) {
-        if (loc == null || sound == null || category == null) return;
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+        Preconditions.checkArgument(sound != null, "Sound cannot be null");
+        Preconditions.checkArgument(category != null, "Category cannot be null");
 
         double x = loc.getX();
         double y = loc.getY();
@@ -1555,7 +1563,10 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void playSound(Location loc, String sound, org.bukkit.SoundCategory category, float volume, float pitch) {
-        if (loc == null || sound == null || category == null) return;
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+        Preconditions.checkArgument(sound != null, "Sound cannot be null");
+        Preconditions.checkArgument(!sound.isBlank(), "Sound cannot be empty");
+        Preconditions.checkArgument(category != null, "Category cannot be null");
 
         double x = loc.getX();
         double y = loc.getY();
@@ -1662,26 +1673,27 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public boolean isGameRule(String rule) {
-        Validate.isTrue(rule != null && !rule.isEmpty(), "Rule cannot be null nor empty");
+        Preconditions.checkArgument(rule != null, "String rule cannot be null");
+        Preconditions.checkArgument(!rule.isBlank(), "String rule cannot be empty");
         return getGameRulesNMS().containsKey(rule);
     }
 
     @Override
     public <T> T getGameRuleValue(GameRule<T> rule) {
-        Validate.notNull(rule, "GameRule cannot be null");
+        Preconditions.checkArgument(rule != null, "GameRule cannot be null");
         return convert(rule, getHandle().getGameRules().getRule(getGameRulesNMS().get(rule.getName())));
     }
 
     @Override
     public <T> T getGameRuleDefault(GameRule<T> rule) {
-        Validate.notNull(rule, "GameRule cannot be null");
+        Preconditions.checkArgument(rule != null, "GameRule cannot be null");
         return convert(rule, getGameRuleDefinitions().get(rule.getName()).createRule());
     }
 
     @Override
     public <T> boolean setGameRule(GameRule<T> rule, T newValue) {
-        Validate.notNull(rule, "GameRule cannot be null");
+        Preconditions.checkArgument(rule != null, "GameRule cannot be null");
-        Validate.notNull(newValue, "GameRule value cannot be null");
+        Preconditions.checkArgument(newValue != null, "GameRule value cannot be null");
 
         if (!isGameRule(rule.getName())) return false;
 
@@ -1781,8 +1793,8 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public <T> void spawnParticle(Particle particle, double x, double y, double z, int count, double offsetX, double offsetY, double offsetZ, double extra, T data, boolean force) {
-        if (data != null && !particle.getDataType().isInstance(data)) {
+        if (data != null) {
-            throw new IllegalArgumentException("data should be " + particle.getDataType() + " got " + data.getClass());
+            Preconditions.checkArgument(particle.getDataType().isInstance(data), "data (%s) should be %s", data.getClass(), particle.getDataType());
         }
         getHandle().sendParticles(
                 null, // Sender
@@ -1878,8 +1890,8 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public Raid locateNearestRaid(Location location, int radius) {
-        Validate.notNull(location, "Location cannot be null");
+        Preconditions.checkArgument(location != null, "Location cannot be null");
-        Validate.isTrue(radius >= 0, "Radius cannot be negative");
+        Preconditions.checkArgument(radius >= 0, "Radius value (%s) cannot be negative", radius);
 
         PersistentRaid persistentRaid = world.getRaids();
         net.minecraft.world.entity.raid.Raid raid = persistentRaid.getNearbyRaid(CraftLocation.toBlockPosition(location), radius * radius);

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java

@@ -31,7 +31,6 @@ import net.minecraft.world.phys.MovingObjectPosition;
 import net.minecraft.world.phys.MovingObjectPositionBlock;
 import net.minecraft.world.phys.Vec3D;
 import net.minecraft.world.phys.shapes.VoxelShape;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
 import org.bukkit.Chunk;
 import org.bukkit.FluidCollisionMode;
@@ -392,10 +391,9 @@ public class CraftBlock implements Block {
         if (o == this) {
             return true;
         }
-        if (!(o instanceof CraftBlock)) {
+        if (!(o instanceof CraftBlock other)) {
             return false;
         }
-        CraftBlock other = (CraftBlock) o;
 
         return this.position.equals(other.position) && this.getWorld().equals(other.getWorld());
     }
@@ -593,15 +591,15 @@ public class CraftBlock implements Block {
 
     @Override
     public RayTraceResult rayTrace(Location start, Vector direction, double maxDistance, FluidCollisionMode fluidCollisionMode) {
-        Validate.notNull(start, "Start location is null!");
+        Preconditions.checkArgument(start != null, "Location start cannot be null");
-        Validate.isTrue(this.getWorld().equals(start.getWorld()), "Start location is from different world!");
+        Preconditions.checkArgument(this.getWorld().equals(start.getWorld()), "Location start cannot be a different world");
         start.checkFinite();
 
-        Validate.notNull(direction, "Direction is null!");
+        Preconditions.checkArgument(direction != null, "Vector direction cannot be null");
         direction.checkFinite();
-        Validate.isTrue(direction.lengthSquared() > 0, "Direction's magnitude is 0!");
+        Preconditions.checkArgument(direction.lengthSquared() > 0, "Direction's magnitude (%s) must be greater than 0", direction.lengthSquared());
 
-        Validate.notNull(fluidCollisionMode, "Fluid collision mode is null!");
+        Preconditions.checkArgument(fluidCollisionMode != null, "FluidCollisionMode cannot be null");
         if (maxDistance < 0.0D) {
             return null;
         }
@@ -634,7 +632,7 @@ public class CraftBlock implements Block {
 
     @Override
     public boolean canPlace(BlockData data) {
-        Preconditions.checkArgument(data != null, "Provided block data is null!");
+        Preconditions.checkArgument(data != null, "BlockData cannot be null");
         net.minecraft.world.level.block.state.IBlockData iblockdata = ((CraftBlockData) data).getState();
         net.minecraft.world.level.World world = this.world.getMinecraftWorld();
 

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockState.java

@@ -80,9 +80,7 @@ public class CraftBlockState implements BlockState {
     }
 
     protected final void ensureNoWorldGeneration() {
-        if (isWorldGeneration()) {
+        Preconditions.checkState(!isWorldGeneration(), "This operation is not supported during world generation!");
-            throw new IllegalStateException("This operation is not supported during world generation!");
-        }
     }
 
     @Override
@@ -142,12 +140,8 @@ public class CraftBlockState implements BlockState {
         if ((mat == null) || (mat.getData() == null)) {
             this.data = CraftMagicNumbers.getBlock(data);
         } else {
-            if ((data.getClass() == mat.getData()) || (data.getClass() == MaterialData.class)) {
+            Preconditions.checkArgument((data.getClass() == mat.getData()) || (data.getClass() == MaterialData.class), "Provided data is not of type %s, found %s", mat.getData().getName(), data.getClass().getName());
             this.data = CraftMagicNumbers.getBlock(data);
-            } else {
-                throw new IllegalArgumentException("Provided data is not of type "
-                        + mat.getData().getName() + ", found " + data.getClass().getName());
-            }
         }
     }
 
@@ -322,8 +316,6 @@ public class CraftBlockState implements BlockState {
     }
 
     protected void requirePlaced() {
-        if (!isPlaced()) {
+        Preconditions.checkState(isPlaced(), "The blockState must be placed to call this method");
-            throw new IllegalStateException("The blockState must be placed to call this method");
-        }
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftStructureBlock.java

@@ -1,12 +1,10 @@
 package org.bukkit.craftbukkit.block;
 
 import com.google.common.base.Preconditions;
-import net.minecraft.core.BlockPosition;
 import net.minecraft.world.level.block.EnumBlockMirror;
 import net.minecraft.world.level.block.EnumBlockRotation;
 import net.minecraft.world.level.block.entity.TileEntityStructure;
 import net.minecraft.world.level.block.state.properties.BlockPropertyStructureMode;
-import org.apache.commons.lang3.Validate;
 import org.bukkit.World;
 import org.bukkit.block.Structure;
 import org.bukkit.block.structure.Mirror;
@@ -32,7 +30,7 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setStructureName(String name) {
-        Preconditions.checkArgument(name != null, "Structure Name cannot be null");
+        Preconditions.checkArgument(name != null, "Structure name cannot be null");
         getSnapshot().setStructureName(name);
     }
 
@@ -43,7 +41,8 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setAuthor(String author) {
-        Preconditions.checkArgument(author != null && !author.isEmpty(), "Author name cannot be null nor empty");
+        Preconditions.checkArgument(author != null, "Author name cannot be null");
+        Preconditions.checkArgument(!author.isBlank(), "Author name cannot be empty");
         getSnapshot().author = author;
     }
 
@@ -60,9 +59,9 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setRelativePosition(BlockVector vector) {
-        Validate.isTrue(isBetween(vector.getBlockX(), -MAX_SIZE, MAX_SIZE), "Structure Size (X) must be between -" + MAX_SIZE + " and " + MAX_SIZE);
+        Preconditions.checkArgument(isBetween(vector.getBlockX(), -MAX_SIZE, MAX_SIZE), "Structure Size (X) must be between -%s and %s but got %s", MAX_SIZE, MAX_SIZE, vector.getBlockX());
-        Validate.isTrue(isBetween(vector.getBlockY(), -MAX_SIZE, MAX_SIZE), "Structure Size (Y) must be between -" + MAX_SIZE + " and " + MAX_SIZE);
+        Preconditions.checkArgument(isBetween(vector.getBlockY(), -MAX_SIZE, MAX_SIZE), "Structure Size (Y) must be between -%s and %s but got %s", MAX_SIZE, MAX_SIZE, vector.getBlockY());
-        Validate.isTrue(isBetween(vector.getBlockZ(), -MAX_SIZE, MAX_SIZE), "Structure Size (Z) must be between -" + MAX_SIZE + " and " + MAX_SIZE);
+        Preconditions.checkArgument(isBetween(vector.getBlockZ(), -MAX_SIZE, MAX_SIZE), "Structure Size (Z) must be between -%s and %s but got %s", MAX_SIZE, MAX_SIZE, vector.getBlockZ());
         getSnapshot().structurePos = CraftBlockVector.toBlockPosition(vector);
     }
 
@@ -73,14 +72,15 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setStructureSize(BlockVector vector) {
-        Validate.isTrue(isBetween(vector.getBlockX(), 0, MAX_SIZE), "Structure Size (X) must be between 0 and " + MAX_SIZE);
+        Preconditions.checkArgument(isBetween(vector.getBlockX(), 0, MAX_SIZE), "Structure Size (X) must be between %s and %s but got %s", 0, MAX_SIZE, vector.getBlockX());
-        Validate.isTrue(isBetween(vector.getBlockY(), 0, MAX_SIZE), "Structure Size (Y) must be between 0 and " + MAX_SIZE);
+        Preconditions.checkArgument(isBetween(vector.getBlockY(), 0, MAX_SIZE), "Structure Size (Y) must be between %s and %s but got %s", 0, MAX_SIZE, vector.getBlockY());
-        Validate.isTrue(isBetween(vector.getBlockZ(), 0, MAX_SIZE), "Structure Size (Z) must be between 0 and " + MAX_SIZE);
+        Preconditions.checkArgument(isBetween(vector.getBlockZ(), 0, MAX_SIZE), "Structure Size (Z) must be between %s and %s but got %s", 0, MAX_SIZE, vector.getBlockZ());
         getSnapshot().structureSize = CraftBlockVector.toBlockPosition(vector);
     }
 
     @Override
     public void setMirror(Mirror mirror) {
+        Preconditions.checkArgument(mirror != null, "Mirror cannot be null");
         getSnapshot().mirror = EnumBlockMirror.valueOf(mirror.name());
     }
 
@@ -91,6 +91,7 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setRotation(StructureRotation rotation) {
+        Preconditions.checkArgument(rotation != null, "StructureRotation cannot be null");
         getSnapshot().rotation = EnumBlockRotation.valueOf(rotation.name());
     }
 
@@ -101,6 +102,7 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setUsageMode(UsageMode mode) {
+        Preconditions.checkArgument(mode != null, "UsageMode cannot be null");
         getSnapshot().mode = BlockPropertyStructureMode.valueOf(mode.name());
     }
 
@@ -141,7 +143,7 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setIntegrity(float integrity) {
-        Validate.isTrue(isBetween(integrity, 0.0f, 1.0f), "Integrity must be between 0.0f and 1.0f");
+        Preconditions.checkArgument(isBetween(integrity, 0.0f, 1.0f), "Integrity must be between 0.0f and 1.0f but got %s", integrity);
         getSnapshot().integrity = integrity;
     }
 
@@ -162,7 +164,7 @@ public class CraftStructureBlock extends CraftBlockEntityState<TileEntityStructu
 
     @Override
     public void setMetadata(String metadata) {
-        Validate.notNull(metadata, "Structure metadata cannot be null");
+        Preconditions.checkArgument(metadata != null, "Structure metadata cannot be null");
         if (getUsageMode() == UsageMode.DATA) {
             getSnapshot().metaData = metadata;
         }

paper-server/src/main/java/org/bukkit/craftbukkit/command/VanillaCommandWrapper.java

@@ -1,6 +1,7 @@
 package org.bukkit.craftbukkit.command;
 
 import com.google.common.base.Joiner;
+import com.google.common.base.Preconditions;
 import com.mojang.brigadier.ParseResults;
 import com.mojang.brigadier.tree.CommandNode;
 import java.util.ArrayList;
@@ -11,7 +12,6 @@ import net.minecraft.commands.CommandListenerWrapper;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.dedicated.DedicatedServer;
 import net.minecraft.world.entity.vehicle.EntityMinecartCommandBlock;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Location;
 import org.bukkit.command.BlockCommandSender;
 import org.bukkit.command.CommandSender;
@@ -48,9 +48,9 @@ public final class VanillaCommandWrapper extends BukkitCommand {
 
     @Override
     public List<String> tabComplete(CommandSender sender, String alias, String[] args, Location location) throws IllegalArgumentException {
-        Validate.notNull(sender, "Sender cannot be null");
+        Preconditions.checkArgument(sender != null, "Sender cannot be null");
-        Validate.notNull(args, "Arguments cannot be null");
+        Preconditions.checkArgument(args != null, "Arguments cannot be null");
-        Validate.notNull(alias, "Alias cannot be null");
+        Preconditions.checkArgument(alias != null, "Alias cannot be null");
 
         CommandListenerWrapper icommandlistener = getListener(sender);
         ParseResults<CommandListenerWrapper> parsed = dispatcher.getDispatcher().parse(toDispatcher(args, getName()), icommandlistener);

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftAbstractHorse.java

@@ -1,9 +1,9 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import java.util.UUID;
 import net.minecraft.world.entity.ai.attributes.GenericAttributes;
 import net.minecraft.world.entity.animal.horse.EntityHorseAbstract;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.inventory.CraftInventoryAbstractHorse;
 import org.bukkit.entity.AbstractHorse;
@@ -34,8 +34,7 @@ public abstract class CraftAbstractHorse extends CraftAnimals implements Abstrac
 
     @Override
     public void setDomestication(int value) {
-        Validate.isTrue(value >= 0, "Domestication cannot be less than zero");
+        Preconditions.checkArgument(value >= 0 && value <= this.getMaxDomestication(), "Domestication level (%s) need to be between %s and %s (max domestication)", value, 0, this.getMaxDomestication());
-        Validate.isTrue(value <= getMaxDomestication(), "Domestication cannot be greater than the max domestication");
         getHandle().setTemper(value);
     }
 
@@ -46,7 +45,7 @@ public abstract class CraftAbstractHorse extends CraftAnimals implements Abstrac
 
     @Override
     public void setMaxDomestication(int value) {
-        Validate.isTrue(value > 0, "Max domestication cannot be zero or less");
+        Preconditions.checkArgument(value > 0, "Max domestication (%s) cannot be zero or less", value);
         getHandle().maxDomestication = value;
     }
 
@@ -57,7 +56,7 @@ public abstract class CraftAbstractHorse extends CraftAnimals implements Abstrac
 
     @Override
     public void setJumpStrength(double strength) {
-        Validate.isTrue(strength >= 0, "Jump strength cannot be less than zero");
+        Preconditions.checkArgument(strength >= 0, "Jump strength (%s) cannot be less than zero", strength);
         getHandle().getAttribute(GenericAttributes.JUMP_STRENGTH).setBaseValue(strength);
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftAreaEffectCloud.java

@@ -1,12 +1,12 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import java.util.List;
 import net.minecraft.world.effect.MobEffect;
 import net.minecraft.world.effect.MobEffectList;
 import net.minecraft.world.entity.EntityAreaEffectCloud;
 import net.minecraft.world.entity.EntityLiving;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Color;
 import org.bukkit.Particle;
 import org.bukkit.craftbukkit.CraftParticle;
@@ -205,7 +205,7 @@ public class CraftAreaEffectCloud extends CraftEntity implements AreaEffectCloud
 
     @Override
     public void setBasePotionData(PotionData data) {
-        Validate.notNull(data, "PotionData cannot be null");
+        Preconditions.checkArgument(data != null, "PotionData cannot be null");
         getHandle().setPotionType(CraftPotionUtil.fromBukkit(data));
     }
 
@@ -222,10 +222,10 @@ public class CraftAreaEffectCloud extends CraftEntity implements AreaEffectCloud
 
     @Override
     public void setSource(ProjectileSource shooter) {
-        if (shooter instanceof CraftLivingEntity) {
+        if (shooter instanceof CraftLivingEntity craftLivingEntity) {
-            getHandle().setOwner((EntityLiving) ((CraftLivingEntity) shooter).getHandle());
+            getHandle().setOwner(craftLivingEntity.getHandle());
         } else {
-            getHandle().setOwner((EntityLiving) null);
+            getHandle().setOwner(null);
         }
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftArrow.java

@@ -3,11 +3,9 @@ package org.bukkit.craftbukkit.entity;
 import com.google.common.base.Preconditions;
 import net.minecraft.core.BlockPosition;
 import net.minecraft.world.entity.projectile.EntityArrow;
-import org.apache.commons.lang.Validate;
 import org.bukkit.block.Block;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.entity.AbstractArrow;
-import org.bukkit.entity.AbstractArrow.PickupStatus;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
 import org.bukkit.projectiles.ProjectileSource;
@@ -20,7 +18,7 @@ public class CraftArrow extends AbstractProjectile implements AbstractArrow {
 
     @Override
     public void setKnockbackStrength(int knockbackStrength) {
-        Validate.isTrue(knockbackStrength >= 0, "Knockback cannot be negative");
+        Preconditions.checkArgument(knockbackStrength >= 0, "Knockback value (%s) cannot be negative", knockbackStrength);
         getHandle().setKnockback(knockbackStrength);
     }
 
@@ -36,7 +34,7 @@ public class CraftArrow extends AbstractProjectile implements AbstractArrow {
 
     @Override
     public void setDamage(double damage) {
-        Preconditions.checkArgument(damage >= 0, "Damage must be positive");
+        Preconditions.checkArgument(damage >= 0, "Damage value (%s) must be positive", damage);
         getHandle().setBaseDamage(damage);
     }
 
@@ -47,7 +45,7 @@ public class CraftArrow extends AbstractProjectile implements AbstractArrow {
 
     @Override
     public void setPierceLevel(int pierceLevel) {
-        Preconditions.checkArgument(0 <= pierceLevel && pierceLevel <= Byte.MAX_VALUE, "Pierce level out of range, expected 0 < level < 127");
+        Preconditions.checkArgument(0 <= pierceLevel && pierceLevel <= Byte.MAX_VALUE, "Pierce level (%s) out of range, expected 0 < level < 127", pierceLevel);
 
         getHandle().setPierceLevel((byte) pierceLevel);
     }
@@ -99,7 +97,7 @@ public class CraftArrow extends AbstractProjectile implements AbstractArrow {
 
     @Override
     public void setPickupStatus(PickupStatus status) {
-        Preconditions.checkNotNull(status, "status");
+        Preconditions.checkArgument(status != null, "PickupStatus cannot be null");
         getHandle().pickup = EntityArrow.PickupStatus.byOrdinal(status.ordinal());
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java

@@ -615,7 +615,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
     @Override
     public void setFreezeTicks(int ticks) {
-        Preconditions.checkArgument(0 <= ticks, "Ticks cannot be less than 0");
+        Preconditions.checkArgument(0 <= ticks, "Ticks (%s) cannot be less than 0", ticks);
 
         getHandle().setTicksFrozen(ticks);
     }
@@ -681,17 +681,12 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
     @Override
     public List<org.bukkit.entity.Entity> getPassengers() {
-        return Lists.newArrayList(Lists.transform(getHandle().passengers, new Function<Entity, org.bukkit.entity.Entity>() {
+        return Lists.newArrayList(Lists.transform(getHandle().passengers, (Function<Entity, org.bukkit.entity.Entity>) input -> input.getBukkitEntity()));
-            @Override
-            public org.bukkit.entity.Entity apply(Entity input) {
-                return input.getBukkitEntity();
-            }
-        }));
     }
 
     @Override
     public boolean addPassenger(org.bukkit.entity.Entity passenger) {
-        Preconditions.checkArgument(passenger != null, "passenger == null");
+        Preconditions.checkArgument(passenger != null, "Entity passenger cannot be null");
         Preconditions.checkArgument(!this.equals(passenger), "Entity cannot ride itself.");
 
         return ((CraftEntity) passenger).getHandle().startRiding(getHandle(), true);
@@ -699,7 +694,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
     @Override
     public boolean removePassenger(org.bukkit.entity.Entity passenger) {
-        Preconditions.checkArgument(passenger != null, "passenger == null");
+        Preconditions.checkArgument(passenger != null, "Entity passenger cannot be null");
 
         ((CraftEntity) passenger).getHandle().stopRiding();
         return true;
@@ -752,9 +747,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
     @Override
     public void setTicksLived(int value) {
-        if (value <= 0) {
+        Preconditions.checkArgument(value > 0, "Age value (%s) must be positive", value);
-            throw new IllegalArgumentException("Age must be at least 1 tick");
-        }
         getHandle().tickCount = value;
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftFireball.java

@@ -1,7 +1,7 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.world.entity.projectile.EntityFireball;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Fireball;
@@ -55,7 +55,7 @@ public class CraftFireball extends AbstractProjectile implements Fireball {
 
     @Override
     public void setDirection(Vector direction) {
-        Validate.notNull(direction, "Direction can not be null");
+        Preconditions.checkArgument(direction != null, "Vector direction cannot be null");
         getHandle().setDirection(direction.getX(), direction.getY(), direction.getZ());
         update(); // SPIGOT-6579
     }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftFishHook.java

@@ -1,14 +1,12 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.core.BlockPosition;
-import net.minecraft.util.MathHelper;
 import net.minecraft.world.entity.projectile.EntityFishingHook;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
 import org.bukkit.entity.FishHook;
-import org.bukkit.entity.FishHook.HookState;
 
 public class CraftFishHook extends CraftProjectile implements FishHook {
     private double biteChance = -1;
@@ -39,8 +37,8 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setMinWaitTime(int minWaitTime) {
+        Preconditions.checkArgument(minWaitTime >= 0 && minWaitTime <= this.getMaxWaitTime(), "The minimum wait time should be between %s and %s (the maximum wait time)", 0, this.getMaxWaitTime());
         EntityFishingHook hook = getHandle();
-        Validate.isTrue(minWaitTime >= 0 && minWaitTime <= this.getMaxWaitTime(), "The minimum wait time should be between 0 and the maximum wait time.");
         hook.minWaitTime = minWaitTime;
     }
 
@@ -51,14 +49,14 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setMaxWaitTime(int maxWaitTime) {
+        Preconditions.checkArgument(maxWaitTime >= 0 && maxWaitTime >= this.getMinWaitTime(), "The maximum wait time should be between %s and %s (the minimum wait time)", 0, this.getMinWaitTime());
         EntityFishingHook hook = getHandle();
-        Validate.isTrue(maxWaitTime >= 0 && maxWaitTime >= this.getMinWaitTime(), "The maximum wait time should be higher than or equal to 0 and the minimum wait time.");
         hook.maxWaitTime = maxWaitTime;
     }
 
     @Override
     public void setWaitTime(int min, int max) {
-        Validate.isTrue(min >= 0 && max >= 0 && min <= max, "The minimum/maximum wait time should be higher than or equal to 0 and the minimum wait time.");
+        Preconditions.checkArgument(min >= 0 && max >= 0 && min <= max, "The minimum/maximum wait time should be higher than or equal to 0 and the minimum wait time");
         getHandle().minWaitTime = min;
         getHandle().maxWaitTime = max;
     }
@@ -70,7 +68,7 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setMinLureTime(int minLureTime) {
-        Validate.isTrue(minLureTime >= 0 && minLureTime <= this.getMaxLureTime(), "The minimum lure time should be between 0 and the maximum wait time.");
+        Preconditions.checkArgument(minLureTime >= 0 && minLureTime <= this.getMaxLureTime(), "The minimum lure time (%s) should be between 0 and %s (the maximum wait time)", minLureTime, this.getMaxLureTime());
         getHandle().minLureTime = minLureTime;
     }
 
@@ -81,13 +79,13 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setMaxLureTime(int maxLureTime) {
-        Validate.isTrue(maxLureTime >= 0 && maxLureTime >= this.getMinLureTime(), "The maximum lure time should be higher than or equal to 0 and the minimum wait time.");
+        Preconditions.checkArgument(maxLureTime >= 0 && maxLureTime >= this.getMinLureTime(), "The maximum lure time (%s) should be higher than or equal to 0 and %s (the minimum wait time)", maxLureTime, this.getMinLureTime());
         getHandle().maxLureTime = maxLureTime;
     }
 
     @Override
     public void setLureTime(int min, int max) {
-        Validate.isTrue(min >= 0 && max >= 0 && min <= max, "The minimum/maximum lure time should be higher than or equal to 0 and the minimum wait time.");
+        Preconditions.checkArgument(min >= 0 && max >= 0 && min <= max, "The minimum/maximum lure time should be higher than or equal to 0 and the minimum wait time.");
         getHandle().minLureTime = min;
         getHandle().maxLureTime = max;
     }
@@ -99,7 +97,7 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setMinLureAngle(float minLureAngle) {
-        Validate.isTrue(minLureAngle <= this.getMaxLureAngle(), "The minimum lure angle should be less than the maximum lure angle.");
+        Preconditions.checkArgument(minLureAngle <= this.getMaxLureAngle(), "The minimum lure angle (%s) should be less than %s (the maximum lure angle)", minLureAngle, this.getMaxLureAngle());
         getHandle().minLureAngle = minLureAngle;
     }
 
@@ -110,13 +108,13 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setMaxLureAngle(float maxLureAngle) {
-        Validate.isTrue(maxLureAngle >= this.getMinLureAngle(), "The minimum lure angle should be less than the maximum lure angle.");
+        Preconditions.checkArgument(maxLureAngle >= this.getMinLureAngle(), "The minimum lure angle (%s) should be less than %s (the maximum lure angle)", maxLureAngle, this.getMinLureAngle());
         getHandle().maxLureAngle = maxLureAngle;
     }
 
     @Override
     public void setLureAngle(float min, float max) {
-        Validate.isTrue(min <= max, "The minimum lure angle should be less than the maximum lure angle.");
+        Preconditions.checkArgument(min <= max, "The minimum lure (%s) angle should be less than the maximum lure angle (%s)", min, max);
         getHandle().minLureAngle = min;
         getHandle().maxLureAngle = max;
     }
@@ -166,7 +164,7 @@ public class CraftFishHook extends CraftProjectile implements FishHook {
 
     @Override
     public void setBiteChance(double chance) {
-        Validate.isTrue(chance >= 0 && chance <= 1, "The bite chance must be between 0 and 1.");
+        Preconditions.checkArgument(chance >= 0 && chance <= 1, "The bite chance must be between 0 and 1");
         this.biteChance = chance;
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftFox.java

@@ -85,8 +85,8 @@ public class CraftFox extends CraftAnimals implements Fox {
 
     @Override
     public void setFirstTrustedPlayer(AnimalTamer player) {
-        if (player == null && getHandle().getEntityData().get(EntityFox.DATA_TRUSTED_ID_1).isPresent()) {
+        if (player == null) {
-            throw new IllegalStateException("Must remove second trusted player first");
+            Preconditions.checkState(getHandle().getEntityData().get(EntityFox.DATA_TRUSTED_ID_1).isEmpty(), "Must remove second trusted player first");
         }
 
         getHandle().getEntityData().set(EntityFox.DATA_TRUSTED_ID_0, player == null ? Optional.empty() : Optional.of(player.getUniqueId()));
@@ -109,8 +109,8 @@ public class CraftFox extends CraftAnimals implements Fox {
 
     @Override
     public void setSecondTrustedPlayer(AnimalTamer player) {
-        if (player != null && !getHandle().getEntityData().get(EntityFox.DATA_TRUSTED_ID_0).isPresent()) {
+        if (player != null) {
-            throw new IllegalStateException("Must add first trusted player first");
+            Preconditions.checkState(getHandle().getEntityData().get(EntityFox.DATA_TRUSTED_ID_0).isPresent(), "Must add first trusted player first");
         }
 
         getHandle().getEntityData().set(EntityFox.DATA_TRUSTED_ID_1, player == null ? Optional.empty() : Optional.of(player.getUniqueId()));

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftHorse.java

@@ -1,16 +1,13 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.world.entity.animal.horse.EntityHorse;
 import net.minecraft.world.entity.animal.horse.HorseColor;
 import net.minecraft.world.entity.animal.horse.HorseStyle;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.inventory.CraftInventoryHorse;
 import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Horse;
-import org.bukkit.entity.Horse.Color;
-import org.bukkit.entity.Horse.Style;
-import org.bukkit.entity.Horse.Variant;
 import org.bukkit.inventory.HorseInventory;
 
 public class CraftHorse extends CraftAbstractHorse implements Horse {
@@ -36,7 +33,7 @@ public class CraftHorse extends CraftAbstractHorse implements Horse {
 
     @Override
     public void setColor(Color color) {
-        Validate.notNull(color, "Color cannot be null");
+        Preconditions.checkArgument(color != null, "Color cannot be null");
         getHandle().setVariantAndMarkings(HorseColor.byId(color.ordinal()), getHandle().getMarkings());
     }
 
@@ -47,7 +44,7 @@ public class CraftHorse extends CraftAbstractHorse implements Horse {
 
     @Override
     public void setStyle(Style style) {
-        Validate.notNull(style, "Style cannot be null");
+        Preconditions.checkArgument(style != null, "Style cannot be null");
         getHandle().setVariantAndMarkings(getHandle().getVariant(), HorseStyle.byId(style.ordinal()));
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftHumanEntity.java

@@ -247,9 +247,7 @@ public class CraftHumanEntity extends CraftLivingEntity implements HumanEntity {
 
     @Override
     public void setGameMode(GameMode mode) {
-        if (mode == null) {
+        Preconditions.checkArgument(mode != null, "GameMode cannot be null");
-            throw new IllegalArgumentException("Mode cannot be null");
-        }
 
         this.mode = mode;
     }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java

@@ -5,7 +5,6 @@ import net.minecraft.core.EnumDirection;
 import net.minecraft.world.entity.decoration.EntityHanging;
 import net.minecraft.world.entity.decoration.EntityItemFrame;
 import net.minecraft.world.level.block.Blocks;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Rotation;
 import org.bukkit.block.BlockFace;
 import org.bukkit.craftbukkit.CraftServer;
@@ -75,7 +74,7 @@ public class CraftItemFrame extends CraftHanging implements ItemFrame {
 
     @Override
     public void setItemDropChance(float chance) {
-        Preconditions.checkArgument(0.0 <= chance && chance <= 1.0, "Chance outside range [0, 1]");
+        Preconditions.checkArgument(0.0 <= chance && chance <= 1.0, "Chance (%s) outside range [0, 1]", chance);
         getHandle().dropChance = chance;
     }
 
@@ -110,7 +109,7 @@ public class CraftItemFrame extends CraftHanging implements ItemFrame {
 
     @Override
     public void setRotation(Rotation rotation) {
-        Validate.notNull(rotation, "Rotation cannot be null");
+        Preconditions.checkArgument(rotation != null, "Rotation cannot be null");
         getHandle().setRotation(toInteger(rotation));
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java

@@ -40,7 +40,6 @@ import net.minecraft.world.entity.projectile.EntityThrownExpBottle;
 import net.minecraft.world.entity.projectile.EntityThrownTrident;
 import net.minecraft.world.entity.projectile.EntityTippedArrow;
 import net.minecraft.world.entity.projectile.EntityWitherSkull;
-import org.apache.commons.lang.Validate;
 import org.bukkit.FluidCollisionMode;
 import org.bukkit.Location;
 import org.bukkit.Material;
@@ -113,9 +112,7 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
     @Override
     public void setHealth(double health) {
         health = (float) health;
-        if ((health < 0) || (health > getMaxHealth())) {
+        Preconditions.checkArgument(health >= 0 && health <= this.getMaxHealth(), "Health value (%s) must be between 0 and %s", health, this.getMaxHealth());
-            throw new IllegalArgumentException("Health must be between 0 and " + getMaxHealth() + "(" + health + ")");
-        }
 
         // during world generation, we don't want to run logic for dropping items and xp
         if (getHandle().generation && health == 0) {
@@ -149,7 +146,7 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
 
     @Override
     public void setMaxHealth(double amount) {
-        Validate.isTrue(amount > 0, "Max health must be greater than 0");
+        Preconditions.checkArgument(amount > 0, "Max health amount (%s) must be greater than 0", amount);
 
         getHandle().getAttribute(GenericAttributes.MAX_HEALTH).setBaseValue(amount);
 
@@ -486,7 +483,7 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
             launch.moveTo(location.getX(), location.getY(), location.getZ(), location.getYaw(), location.getPitch());
         }
 
-        Validate.notNull(launch, "Projectile not supported");
+        Preconditions.checkArgument(launch != null, "Projectile (%s) not supported", projectile.getName());
 
         if (velocity != null) {
             ((T) launch.getBukkitEntity()).setVelocity(velocity);
@@ -562,9 +559,7 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
 
     @Override
     public Entity getLeashHolder() throws IllegalStateException {
-        if (!isLeashed()) {
+        Preconditions.checkState(isLeashed(), "Entity not leashed");
-            throw new IllegalStateException("Entity not leashed");
-        }
         return ((EntityInsentient) getHandle()).getLeashHolder().getBukkitEntity();
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java

@@ -92,7 +92,6 @@ import net.minecraft.world.level.border.IWorldBorderListener;
 import net.minecraft.world.level.saveddata.maps.MapIcon;
 import net.minecraft.world.level.saveddata.maps.WorldMap;
 import net.minecraft.world.phys.Vec3D;
-import org.apache.commons.lang.Validate;
 import org.bukkit.BanList;
 import org.bukkit.Bukkit;
 import org.bukkit.DyeColor;
@@ -242,15 +241,13 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void sendRawMessage(String message) {
-        if (getHandle().connection == null) return;
+        this.sendRawMessage(null, message);
-
-        for (IChatBaseComponent component : CraftChatMessage.fromString(message)) {
-            getHandle().sendSystemMessage(component);
-        }
     }
 
     @Override
     public void sendRawMessage(UUID sender, String message) {
+        Preconditions.checkArgument(message != null, "message cannot be null");
+
         if (getHandle().connection == null) return;
 
         for (IChatBaseComponent component : CraftChatMessage.fromString(message)) {
@@ -382,6 +379,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setCompassTarget(Location loc) {
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+
         if (getHandle().connection == null) return;
 
         // Do not directly assign here, from the packethandler we'll assign it.
@@ -395,6 +394,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void chat(String msg) {
+        Preconditions.checkArgument(msg != null, "msg cannot be null");
+
         if (getHandle().connection == null) return;
 
         getHandle().connection.chat(msg, PlayerChatMessage.system(msg), false);
@@ -402,109 +403,44 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public boolean performCommand(String command) {
+        Preconditions.checkArgument(command != null, "command cannot be null");
         return server.dispatchCommand(this, command);
     }
 
     @Override
     public void playNote(Location loc, byte instrument, byte note) {
-        if (getHandle().connection == null) return;
+        playNote(loc, Instrument.getByType(instrument), new Note(note));
-
-        String instrumentName = null;
-        switch (instrument) {
-        case 0:
-            instrumentName = "harp";
-            break;
-        case 1:
-            instrumentName = "basedrum";
-            break;
-        case 2:
-            instrumentName = "snare";
-            break;
-        case 3:
-            instrumentName = "hat";
-            break;
-        case 4:
-            instrumentName = "bass";
-            break;
-        case 5:
-            instrumentName = "flute";
-            break;
-        case 6:
-            instrumentName = "bell";
-            break;
-        case 7:
-            instrumentName = "guitar";
-            break;
-        case 8:
-            instrumentName = "chime";
-            break;
-        case 9:
-            instrumentName = "xylophone";
-            break;
-        }
-
-        float f = (float) Math.pow(2.0D, (note - 12.0D) / 12.0D);
-        getHandle().connection.send(new PacketPlayOutNamedSoundEffect(BuiltInRegistries.SOUND_EVENT.wrapAsHolder(CraftSound.getSoundEffect("block.note_block." + instrumentName)), net.minecraft.sounds.SoundCategory.RECORDS, loc.getBlockX(), loc.getBlockY(), loc.getBlockZ(), 3.0f, f, getHandle().getRandom().nextLong()));
     }
 
     @Override
     public void playNote(Location loc, Instrument instrument, Note note) {
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+        Preconditions.checkArgument(instrument != null, "Instrument cannot be null");
+        Preconditions.checkArgument(note != null, "Note cannot be null");
+
         if (getHandle().connection == null) return;
 
-        String instrumentName = null;
+        String instrumentName = switch (instrument.ordinal()) {
-        switch (instrument.ordinal()) {
+            case 0 -> "harp";
-            case 0:
+            case 1 -> "basedrum";
-                instrumentName = "harp";
+            case 2 -> "snare";
-                break;
+            case 3 -> "hat";
-            case 1:
+            case 4 -> "bass";
-                instrumentName = "basedrum";
+            case 5 -> "flute";
-                break;
+            case 6 -> "bell";
-            case 2:
+            case 7 -> "guitar";
-                instrumentName = "snare";
+            case 8 -> "chime";
-                break;
+            case 9 -> "xylophone";
-            case 3:
+            case 10 -> "iron_xylophone";
-                instrumentName = "hat";
+            case 11 -> "cow_bell";
-                break;
+            case 12 -> "didgeridoo";
-            case 4:
+            case 13 -> "bit";
-                instrumentName = "bass";
+            case 14 -> "banjo";
-                break;
+            case 15 -> "pling";
-            case 5:
+            case 16 -> "xylophone";
-                instrumentName = "flute";
+            default -> null;
-                break;
+        };
-            case 6:
+
-                instrumentName = "bell";
-                break;
-            case 7:
-                instrumentName = "guitar";
-                break;
-            case 8:
-                instrumentName = "chime";
-                break;
-            case 9:
-                instrumentName = "xylophone";
-                break;
-            case 10:
-                instrumentName = "iron_xylophone";
-                break;
-            case 11:
-                instrumentName = "cow_bell";
-                break;
-            case 12:
-                instrumentName = "didgeridoo";
-                break;
-            case 13:
-                instrumentName = "bit";
-                break;
-            case 14:
-                instrumentName = "banjo";
-                break;
-            case 15:
-                instrumentName = "pling";
-                break;
-            case 16:
-                instrumentName = "xylophone";
-                break;
-        }
         float f = (float) Math.pow(2.0D, (note.getId() - 12.0D) / 12.0D);
         getHandle().connection.send(new PacketPlayOutNamedSoundEffect(BuiltInRegistries.SOUND_EVENT.wrapAsHolder(CraftSound.getSoundEffect("block.note_block." + instrumentName)), net.minecraft.sounds.SoundCategory.RECORDS, loc.getBlockX(), loc.getBlockY(), loc.getBlockZ(), 3.0f, f, getHandle().getRandom().nextLong()));
     }
@@ -521,17 +457,26 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void playSound(Location loc, Sound sound, org.bukkit.SoundCategory category, float volume, float pitch) {
-        if (loc == null || sound == null || category == null || getHandle().connection == null) return;
+        Preconditions.checkArgument(sound != null, "Sound cannot be null");
+        Preconditions.checkArgument(category != null, "Category cannot be null");
 
-        PacketPlayOutNamedSoundEffect packet = new PacketPlayOutNamedSoundEffect(BuiltInRegistries.SOUND_EVENT.wrapAsHolder(CraftSound.getSoundEffect(sound)), net.minecraft.sounds.SoundCategory.valueOf(category.name()), loc.getX(), loc.getY(), loc.getZ(), volume, pitch, getHandle().getRandom().nextLong());
+        playSound0(loc, BuiltInRegistries.SOUND_EVENT.wrapAsHolder(CraftSound.getSoundEffect(sound)), net.minecraft.sounds.SoundCategory.valueOf(category.name()), volume, pitch);
-        getHandle().connection.send(packet);
     }
 
     @Override
     public void playSound(Location loc, String sound, org.bukkit.SoundCategory category, float volume, float pitch) {
-        if (loc == null || sound == null || category == null || getHandle().connection == null) return;
+        Preconditions.checkArgument(sound != null, "sound cannot be null");
+        Preconditions.checkArgument(category != null, "Category cannot be null");
 
-        PacketPlayOutNamedSoundEffect packet = new PacketPlayOutNamedSoundEffect(Holder.direct(SoundEffect.createVariableRangeEvent(new MinecraftKey(sound))), net.minecraft.sounds.SoundCategory.valueOf(category.name()), loc.getX(), loc.getY(), loc.getZ(), volume, pitch, getHandle().getRandom().nextLong());
+        playSound0(loc, Holder.direct(SoundEffect.createVariableRangeEvent(new MinecraftKey(sound))), net.minecraft.sounds.SoundCategory.valueOf(category.name()), volume, pitch);
+    }
+
+    private void playSound0(Location loc, Holder<SoundEffect> soundEffectHolder, net.minecraft.sounds.SoundCategory categoryNMS, float volume, float pitch) {
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+
+        if (getHandle().connection == null) return;
+
+        PacketPlayOutNamedSoundEffect packet = new PacketPlayOutNamedSoundEffect(soundEffectHolder, categoryNMS, loc.getX(), loc.getY(), loc.getZ(), volume, pitch, getHandle().getRandom().nextLong());
         getHandle().connection.send(packet);
     }
 
@@ -547,17 +492,29 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void playSound(org.bukkit.entity.Entity entity, Sound sound, org.bukkit.SoundCategory category, float volume, float pitch) {
-        if (!(entity instanceof CraftEntity craftEntity) || sound == null || category == null || getHandle().connection == null) return;
+        Preconditions.checkArgument(category != null, "Category cannot be null");
+        Preconditions.checkArgument(sound != null, "Sound cannot be null");
 
-        PacketPlayOutEntitySound packet = new PacketPlayOutEntitySound(BuiltInRegistries.SOUND_EVENT.wrapAsHolder(CraftSound.getSoundEffect(sound)), net.minecraft.sounds.SoundCategory.valueOf(category.name()), craftEntity.getHandle(), volume, pitch, getHandle().getRandom().nextLong());
+        playSound0(entity, BuiltInRegistries.SOUND_EVENT.wrapAsHolder(CraftSound.getSoundEffect(sound)), net.minecraft.sounds.SoundCategory.valueOf(category.name()), volume, pitch);
-        getHandle().connection.send(packet);
     }
 
     @Override
     public void playSound(org.bukkit.entity.Entity entity, String sound, org.bukkit.SoundCategory category, float volume, float pitch) {
-        if (!(entity instanceof CraftEntity craftEntity) || sound == null || category == null || getHandle().connection == null) return;
+        Preconditions.checkArgument(category != null, "Category cannot be null");
+        Preconditions.checkArgument(sound != null, "sound cannot be null");
 
-        PacketPlayOutEntitySound packet = new PacketPlayOutEntitySound(Holder.direct(SoundEffect.createVariableRangeEvent(new MinecraftKey(sound))), net.minecraft.sounds.SoundCategory.valueOf(category.name()), craftEntity.getHandle(), volume, pitch, getHandle().getRandom().nextLong());
+        playSound0(entity, Holder.direct(SoundEffect.createVariableRangeEvent(new MinecraftKey(sound))), net.minecraft.sounds.SoundCategory.valueOf(category.name()), volume, pitch);
+    }
+
+    private void playSound0(org.bukkit.entity.Entity entity, Holder<SoundEffect> soundEffectHolder, net.minecraft.sounds.SoundCategory categoryNMS, float volume, float pitch) {
+        Preconditions.checkArgument(entity != null, "Entity cannot be null");
+        Preconditions.checkArgument(soundEffectHolder != null, "Holder of SoundEffect cannot be null");
+        Preconditions.checkArgument(categoryNMS != null, "SoundCategory cannot be null");
+
+        if (getHandle().connection == null) return;
+        if (!(entity instanceof CraftEntity craftEntity)) return;
+
+        PacketPlayOutEntitySound packet = new PacketPlayOutEntitySound(soundEffectHolder, categoryNMS, craftEntity.getHandle(), volume, pitch, getHandle().getRandom().nextLong());
         getHandle().connection.send(packet);
     }
 
@@ -599,6 +556,9 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void playEffect(Location loc, Effect effect, int data) {
+        Preconditions.checkArgument(effect != null, "Effect cannot be null");
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
+
         if (getHandle().connection == null) return;
 
         int packetData = effect.getId();
@@ -608,11 +568,13 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public <T> void playEffect(Location loc, Effect effect, T data) {
+        Preconditions.checkArgument(effect != null, "Effect cannot be null");
         if (data != null) {
-            Validate.isTrue(effect.getData() != null && effect.getData().isAssignableFrom(data.getClass()), "Wrong kind of data for this effect!");
+            Preconditions.checkArgument(effect.getData() != null, "Effect.%s does not have a valid Data", effect);
+            Preconditions.checkArgument(effect.getData().isAssignableFrom(data.getClass()), "%s data cannot be used for the %s effect", data.getClass().getName(), effect);
         } else {
             // Special case: the axis is optional for ELECTRIC_SPARK
-            Validate.isTrue(effect.getData() == null || effect == Effect.ELECTRIC_SPARK, "Wrong kind of data for this effect!");
+            Preconditions.checkArgument(effect.getData() == null || effect == Effect.ELECTRIC_SPARK, "Wrong kind of data for the %s effect", effect);
         }
 
         int datavalue = CraftEffect.getDataValue(effect, data);
@@ -725,19 +687,15 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void sendSignChange(Location loc, String[] lines, DyeColor dyeColor, boolean hasGlowingText) {
-        if (getHandle().connection == null) {
+        Preconditions.checkArgument(loc != null, "Location cannot be null");
-            return;
+        Preconditions.checkArgument(dyeColor != null, "DyeColor cannot be null");
-        }
 
         if (lines == null) {
             lines = new String[4];
         }
+        Preconditions.checkArgument(lines.length < 4, "lines (%s) must be lower than 4", lines.length);
 
-        Validate.notNull(loc, "Location can not be null");
+        if (getHandle().connection == null) return;
-        Validate.notNull(dyeColor, "DyeColor can not be null");
-        if (lines.length < 4) {
-            throw new IllegalArgumentException("Must have at least 4 lines");
-        }
 
         IChatBaseComponent[] components = CraftSign.sanitizeLines(lines);
         TileEntitySign sign = new TileEntitySign(CraftLocation.toBlockPosition(loc), Blocks.OAK_SIGN.defaultBlockState());
@@ -758,8 +716,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void sendEquipmentChange(LivingEntity entity, Map<EquipmentSlot, ItemStack> items) {
-        Preconditions.checkArgument(entity != null, "entity must not be null");
+        Preconditions.checkArgument(entity != null, "Entity cannot be null");
-        Preconditions.checkArgument(items != null, "items must not be null");
+        Preconditions.checkArgument(items != null, "items cannot be null");
 
         if (getHandle().connection == null) {
             return;
@@ -1232,12 +1190,9 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setGameMode(GameMode mode) {
+        Preconditions.checkArgument(mode != null, "GameMode cannot be null");
         if (getHandle().connection == null) return;
 
-        if (mode == null) {
-            throw new IllegalArgumentException("Mode cannot be null");
-        }
-
         getHandle().setGameMode(EnumGamemode.byId(mode.getValue()));
     }
 
@@ -1334,14 +1289,14 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void hideEntity(Plugin plugin, org.bukkit.entity.Entity entity) {
-        Validate.notNull(plugin, "Plugin cannot be null");
+        Preconditions.checkArgument(plugin != null, "Plugin cannot be null");
-        Validate.isTrue(plugin.isEnabled(), "Plugin attempted to hide player while disabled");
+        Preconditions.checkArgument(plugin.isEnabled(), "Plugin (%s) cannot be disabled", plugin.getName());
 
         hideEntity0(plugin, entity);
     }
 
     private void hideEntity0(@Nullable Plugin plugin, org.bukkit.entity.Entity entity) {
-        Validate.notNull(entity, "hidden entity cannot be null");
+        Preconditions.checkArgument(entity != null, "Entity hidden cannot be null");
         if (getHandle().connection == null) return;
         if (equals(entity)) return;
 
@@ -1416,14 +1371,14 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void showEntity(Plugin plugin, org.bukkit.entity.Entity entity) {
-        Validate.notNull(plugin, "Plugin cannot be null");
+        Preconditions.checkArgument(plugin != null, "Plugin cannot be null");
         // Don't require that plugin be enabled. A plugin must be allowed to call
         // showPlayer during its onDisable() method.
         showEntity0(plugin, entity);
     }
 
     private void showEntity0(@Nullable Plugin plugin, org.bukkit.entity.Entity entity) {
-        Validate.notNull(entity, "shown entity cannot be null");
+        Preconditions.checkArgument(entity != null, "Entity show cannot be null");
         if (getHandle().connection == null) return;
         if (equals(entity)) return;
 
@@ -1661,10 +1616,10 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setResourcePack(String url, byte[] hash, String prompt, boolean force) {
-        Validate.notNull(url, "Resource pack URL cannot be null");
+        Preconditions.checkArgument(url != null, "Resource pack URL cannot be null");
 
         if (hash != null) {
-            Validate.isTrue(hash.length == 20, "Resource pack hash should be 20 bytes long but was " + hash.length);
+            Preconditions.checkArgument(hash.length == 20, "Resource pack hash should be 20 bytes long but was %s", hash.length);
 
             getHandle().sendTexturePack(url, BaseEncoding.base16().lowerCase().encode(hash), force, CraftChatMessage.fromStringOrNull(prompt, true));
         } else {
@@ -1759,8 +1714,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setFlying(boolean value) {
-        if (!getAllowFlight() && value) {
+        if (!getAllowFlight()) {
-            throw new IllegalArgumentException("Cannot make player fly if getAllowFlight() is false");
+            Preconditions.checkArgument(!value, "Player is not allowed to fly (check #getAllowFlight())");
         }
 
         getHandle().getAbilities().flying = value;
@@ -1826,21 +1781,13 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
     }
 
     private void validateSpeed(float value) {
-        if (value < 0) {
+        Preconditions.checkArgument(value <= 1f && value >= -1f, "Speed value (%s) need to be between -1f and 1f", value);
-            if (value < -1f) {
-                throw new IllegalArgumentException(value + " is too low");
-            }
-        } else {
-            if (value > 1f) {
-                throw new IllegalArgumentException(value + " is too high");
-            }
-        }
     }
 
     @Override
     public void setMaxHealth(double amount) {
         super.setMaxHealth(amount);
-        this.health = Math.min(this.health, health);
+        this.health = Math.min(this.health, amount);
         getHandle().resetSentInfo();
     }
 
@@ -1857,21 +1804,16 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setScoreboard(Scoreboard scoreboard) {
-        Validate.notNull(scoreboard, "Scoreboard cannot be null");
+        Preconditions.checkArgument(scoreboard != null, "Scoreboard cannot be null");
-        PlayerConnection playerConnection = getHandle().connection;
+        Preconditions.checkState(getHandle().connection != null, "Cannot set scoreboard yet (invalid player connection)");
-        if (playerConnection == null) {
+        Preconditions.checkState(getHandle().connection.isDisconnected(), "Cannot set scoreboard for invalid CraftPlayer (player is disconnected)");
-            throw new IllegalStateException("Cannot set scoreboard yet");
-        }
-        if (playerConnection.isDisconnected()) {
-            throw new IllegalStateException("Cannot set scoreboard for invalid CraftPlayer");
-        }
 
         this.server.getScoreboardManager().setPlayerBoard(this, scoreboard);
     }
 
     @Override
     public void setHealthScale(double value) {
-        Validate.isTrue((float) value > 0F, "Must be greater than 0");
+        Preconditions.checkArgument(value > 0F, "Health value (%s) must be greater than 0", value);
         healthScale = value;
         scaledHealth = true;
         updateScaledHealth();
@@ -2044,8 +1986,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public <T> void spawnParticle(Particle particle, double x, double y, double z, int count, double offsetX, double offsetY, double offsetZ, double extra, T data) {
-        if (data != null && !particle.getDataType().isInstance(data)) {
+        if (data != null) {
-            throw new IllegalArgumentException("data should be " + particle.getDataType() + " got " + data.getClass());
+            Preconditions.checkArgument(particle.getDataType().isInstance(data), "data (%s) should be %s", data.getClass(), particle.getDataType());
         }
         PacketPlayOutWorldParticles packetplayoutworldparticles = new PacketPlayOutWorldParticles(CraftParticle.toNMS(particle, data), true, (float) x, (float) y, (float) z, (float) offsetX, (float) offsetY, (float) offsetZ, (float) extra, count);
         getHandle().connection.send(packetplayoutworldparticles);
@@ -2087,8 +2029,8 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void openBook(ItemStack book) {
-        Validate.isTrue(book != null, "book == null");
+        Preconditions.checkArgument(book != null, "ItemStack cannot be null");
-        Validate.isTrue(book.getType() == Material.WRITTEN_BOOK, "Book must be Material.WRITTEN_BOOK");
+        Preconditions.checkArgument(book.getType() == Material.WRITTEN_BOOK, "ItemStack Material (%s) must be Material.WRITTEN_BOOK", book.getType());
 
         ItemStack hand = getInventory().getItemInMainHand();
         getInventory().setItemInMainHand(book);

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftThrownPotion.java

@@ -1,11 +1,11 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import java.util.Collection;
 import net.minecraft.world.effect.MobEffect;
 import net.minecraft.world.entity.projectile.EntityPotion;
 import net.minecraft.world.item.alchemy.PotionUtil;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
@@ -36,11 +36,8 @@ public class CraftThrownPotion extends CraftThrowableProjectile implements Throw
 
     @Override
     public void setItem(ItemStack item) {
-        // The ItemStack must not be null.
+        Preconditions.checkArgument(item != null, "ItemStack cannot be null");
-        Validate.notNull(item, "ItemStack cannot be null.");
+        Preconditions.checkArgument(item.getType() == Material.LINGERING_POTION || item.getType() == Material.SPLASH_POTION, "ItemStack material must be Material.LINGERING_POTION or Material.SPLASH_POTION but was Material.%s", item.getType());
-
-        // The ItemStack must be a potion.
-        Validate.isTrue(item.getType() == Material.LINGERING_POTION || item.getType() == Material.SPLASH_POTION, "ItemStack must be a lingering or splash potion. This item stack was " + item.getType() + ".");
 
         getHandle().setItem(CraftItemStack.asNMSCopy(item));
     }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftTippedArrow.java

@@ -1,11 +1,11 @@
 package org.bukkit.craftbukkit.entity;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import java.util.List;
 import net.minecraft.world.effect.MobEffect;
 import net.minecraft.world.effect.MobEffectList;
 import net.minecraft.world.entity.projectile.EntityTippedArrow;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Color;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.potion.CraftPotionUtil;
@@ -105,7 +105,7 @@ public class CraftTippedArrow extends CraftArrow implements Arrow {
 
     @Override
     public void setBasePotionData(PotionData data) {
-        Validate.notNull(data, "PotionData cannot be null");
+        Preconditions.checkArgument(data != null, "PotionData cannot be null");
         getHandle().setPotionType(CraftPotionUtil.fromBukkit(data));
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftVillager.java

@@ -10,7 +10,6 @@ import net.minecraft.world.entity.npc.EntityVillager;
 import net.minecraft.world.entity.npc.VillagerProfession;
 import net.minecraft.world.level.block.BlockBed;
 import net.minecraft.world.level.block.state.IBlockData;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Location;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.util.CraftLocation;
@@ -55,7 +54,7 @@ public class CraftVillager extends CraftAbstractVillager implements Villager {
 
     @Override
     public void setProfession(Profession profession) {
-        Validate.notNull(profession);
+        Preconditions.checkArgument(profession != null, "Profession cannot be null");
         getHandle().setVillagerData(getHandle().getVillagerData().setProfession(CraftVillager.bukkitToNmsProfession(profession)));
     }
 
@@ -66,7 +65,7 @@ public class CraftVillager extends CraftAbstractVillager implements Villager {
 
     @Override
     public void setVillagerType(Type type) {
-        Validate.notNull(type);
+        Preconditions.checkArgument(type != null, "Type cannot be null");
         getHandle().setVillagerData(getHandle().getVillagerData().setType(BuiltInRegistries.VILLAGER_TYPE.get(CraftNamespacedKey.toMinecraft(type.getKey()))));
     }
 
@@ -77,7 +76,7 @@ public class CraftVillager extends CraftAbstractVillager implements Villager {
 
     @Override
     public void setVillagerLevel(int level) {
-        Preconditions.checkArgument(1 <= level && level <= 5, "level must be between [1, 5]");
+        Preconditions.checkArgument(1 <= level && level <= 5, "level (%s) must be between [1, 5]", level);
 
         getHandle().setVillagerData(getHandle().getVillagerData().setLevel(level));
     }
@@ -89,7 +88,7 @@ public class CraftVillager extends CraftAbstractVillager implements Villager {
 
     @Override
     public void setVillagerExperience(int experience) {
-        Preconditions.checkArgument(experience >= 0, "Experience must be positive");
+        Preconditions.checkArgument(experience >= 0, "Experience (%s) must be positive", experience);
 
         getHandle().setVillagerXp(experience);
     }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftVillagerZombie.java

@@ -2,12 +2,10 @@ package org.bukkit.craftbukkit.entity;
 
 import com.google.common.base.Preconditions;
 import java.util.Locale;
-import java.util.UUID;
 import net.minecraft.core.registries.BuiltInRegistries;
 import net.minecraft.resources.MinecraftKey;
 import net.minecraft.world.effect.MobEffects;
 import net.minecraft.world.entity.monster.EntityZombieVillager;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.craftbukkit.CraftServer;
@@ -44,7 +42,7 @@ public class CraftVillagerZombie extends CraftZombie implements ZombieVillager {
 
     @Override
     public void setVillagerProfession(Villager.Profession profession) {
-        Validate.notNull(profession);
+        Preconditions.checkArgument(profession != null, "Villager.Profession cannot be null");
         getHandle().setVillagerData(getHandle().getVillagerData().setProfession(BuiltInRegistries.VILLAGER_PROFESSION.get(new MinecraftKey(profession.name().toLowerCase(Locale.ROOT)))));
     }
 
@@ -55,7 +53,7 @@ public class CraftVillagerZombie extends CraftZombie implements ZombieVillager {
 
     @Override
     public void setVillagerType(Villager.Type type) {
-        Validate.notNull(type);
+        Preconditions.checkArgument(type != null, "Villager.Type cannot be null");
         getHandle().setVillagerData(getHandle().getVillagerData().setType(BuiltInRegistries.VILLAGER_TYPE.get(CraftNamespacedKey.toMinecraft(type.getKey()))));
     }
 
@@ -79,7 +77,7 @@ public class CraftVillagerZombie extends CraftZombie implements ZombieVillager {
             getHandle().conversionStarter = null;
             getHandle().removeEffect(MobEffects.DAMAGE_BOOST, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.CONVERSION);
         } else {
-            getHandle().startConverting((UUID) null, time);
+            getHandle().startConverting(null, time);
         }
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java

@@ -2,6 +2,7 @@ package org.bukkit.craftbukkit.event;
 
 import com.google.common.base.Function;
 import com.google.common.base.Functions;
+import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 import com.mojang.datafixers.util.Either;
 import java.net.InetAddress;
@@ -1610,9 +1611,8 @@ public class CraftEventFactory {
         PotionEffect bukkitOldEffect = (oldEffect == null) ? null : CraftPotionUtil.toBukkit(oldEffect);
         PotionEffect bukkitNewEffect = (newEffect == null) ? null : CraftPotionUtil.toBukkit(newEffect);
 
-        if (bukkitOldEffect == null && bukkitNewEffect == null) {
+        Preconditions.checkState(bukkitOldEffect != null, "Old and new potion is null");
-            throw new IllegalStateException("Old and new potion effect are both null");
+        Preconditions.checkState(bukkitNewEffect != null, "New potion effect is null");
-        }
 
         EntityPotionEffectEvent event = new EntityPotionEffectEvent((LivingEntity) entity.getBukkitEntity(), bukkitOldEffect, bukkitNewEffect, cause, action, willOverride);
         Bukkit.getPluginManager().callEvent(event);

paper-server/src/main/java/org/bukkit/craftbukkit/generator/CraftChunkData.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.generator;
 
+import com.google.common.base.Preconditions;
 import java.lang.ref.WeakReference;
 import net.minecraft.core.BlockPosition;
 import net.minecraft.world.level.block.Blocks;
@@ -38,9 +39,7 @@ public final class CraftChunkData implements ChunkGenerator.ChunkData {
     public IChunkAccess getHandle() {
         IChunkAccess access = weakChunk.get();
 
-        if (access == null) {
+        Preconditions.checkState(access != null, "IChunkAccess no longer present, are you using it in a different tick?");
-            throw new IllegalStateException("IChunkAccess no longer present, are you using it in a different tick?");
-        }
 
         return access;
     }

paper-server/src/main/java/org/bukkit/craftbukkit/generator/CraftLimitedRegion.java

@@ -68,9 +68,7 @@ public class CraftLimitedRegion extends CraftRegionAccessor implements LimitedRe
     public GeneratorAccessSeed getHandle() {
         GeneratorAccessSeed handle = weakAccess.get();
 
-        if (handle == null) {
+        Preconditions.checkState(handle != null, "GeneratorAccessSeed no longer present, are you using it in a different tick?");
-            throw new IllegalStateException("GeneratorAccessSeed no longer present, are you using it in a different tick?");
-        }
 
         return handle;
     }

paper-server/src/main/java/org/bukkit/craftbukkit/help/CommandAliasHelpTopic.java

@@ -1,6 +1,6 @@
 package org.bukkit.craftbukkit.help;
 
-import org.apache.commons.lang.Validate;
+import com.google.common.base.Preconditions;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.help.HelpMap;
@@ -15,12 +15,13 @@ public class CommandAliasHelpTopic extends HelpTopic {
         this.aliasFor = aliasFor.startsWith("/") ? aliasFor : "/" + aliasFor;
         this.helpMap = helpMap;
         this.name = alias.startsWith("/") ? alias : "/" + alias;
-        Validate.isTrue(!this.name.equals(this.aliasFor), "Command " + this.name + " cannot be alias for itself");
+        Preconditions.checkArgument(!this.name.equals(this.aliasFor), "Command %s cannot be alias for itself", this.name);
         this.shortText = ChatColor.YELLOW + "Alias for " + ChatColor.WHITE + this.aliasFor;
     }
 
     @Override
     public String getFullText(CommandSender forWho) {
+        Preconditions.checkArgument(forWho != null, "CommandServer forWho cannot be null");
         StringBuilder sb = new StringBuilder(shortText);
         HelpTopic aliasForTopic = helpMap.getHelpTopic(aliasFor);
         if (aliasForTopic != null) {
@@ -32,6 +33,7 @@ public class CommandAliasHelpTopic extends HelpTopic {
 
     @Override
     public boolean canSee(CommandSender commandSender) {
+        Preconditions.checkArgument(commandSender != null, "CommandServer cannot be null");
         if (amendedPermission == null) {
             HelpTopic aliasForTopic = helpMap.getHelpTopic(aliasFor);
             if (aliasForTopic != null) {

paper-server/src/main/java/org/bukkit/craftbukkit/help/SimpleHelpMap.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.help;
 
+import com.google.common.base.Preconditions;
 import com.google.common.base.Predicate;
 import com.google.common.base.Predicates;
 import com.google.common.collect.Collections2;
@@ -223,9 +224,7 @@ public class SimpleHelpMap implements HelpMap {
 
     @Override
     public void registerHelpTopicFactory(Class commandClass, HelpTopicFactory factory) {
-        if (!Command.class.isAssignableFrom(commandClass) && !CommandExecutor.class.isAssignableFrom(commandClass)) {
+        Preconditions.checkArgument(Command.class.isAssignableFrom(commandClass) && CommandExecutor.class.isAssignableFrom(commandClass), "commandClass (%s) must implement either Command or CommandExecutor", commandClass.getName());
-            throw new IllegalArgumentException("commandClass must implement either Command or CommandExecutor!");
-        }
         topicFactoryMap.put(commandClass, factory);
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventory.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import java.util.HashMap;
 import java.util.List;
 import java.util.ListIterator;
@@ -21,7 +22,6 @@ import net.minecraft.world.level.block.entity.TileEntityJukeBox;
 import net.minecraft.world.level.block.entity.TileEntityLectern;
 import net.minecraft.world.level.block.entity.TileEntityShulkerBox;
 import net.minecraft.world.level.block.entity.TileEntitySmoker;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.craftbukkit.util.CraftLegacy;
@@ -84,9 +84,7 @@ public class CraftInventory implements Inventory {
 
     @Override
     public void setContents(ItemStack[] items) {
-        if (getSize() < items.length) {
+        Preconditions.checkArgument(getSize() < items.length, "Invalid inventory size (%s); expected %s or less", items.length, getSize());
-            throw new IllegalArgumentException("Invalid inventory size; expected " + getSize() + " or less");
-        }
 
         for (int i = 0; i < getSize(); i++) {
             if (i >= items.length) {
@@ -104,7 +102,7 @@ public class CraftInventory implements Inventory {
 
     @Override
     public boolean contains(Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         material = CraftLegacy.fromLegacy(material);
         for (ItemStack item : getStorageContents()) {
             if (item != null && item.getType() == material) {
@@ -129,7 +127,7 @@ public class CraftInventory implements Inventory {
 
     @Override
     public boolean contains(Material material, int amount) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         material = CraftLegacy.fromLegacy(material);
         if (amount <= 0) {
             return true;
@@ -178,9 +176,9 @@ public class CraftInventory implements Inventory {
 
     @Override
     public HashMap<Integer, ItemStack> all(Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         material = CraftLegacy.fromLegacy(material);
-        HashMap<Integer, ItemStack> slots = new HashMap<Integer, ItemStack>();
+        HashMap<Integer, ItemStack> slots = new HashMap<>();
 
         ItemStack[] inventory = getStorageContents();
         for (int i = 0; i < inventory.length; i++) {
@@ -194,7 +192,7 @@ public class CraftInventory implements Inventory {
 
     @Override
     public HashMap<Integer, ItemStack> all(ItemStack item) {
-        HashMap<Integer, ItemStack> slots = new HashMap<Integer, ItemStack>();
+        HashMap<Integer, ItemStack> slots = new HashMap<>();
         if (item != null) {
             ItemStack[] inventory = getStorageContents();
             for (int i = 0; i < inventory.length; i++) {
@@ -208,7 +206,7 @@ public class CraftInventory implements Inventory {
 
     @Override
     public int first(Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         material = CraftLegacy.fromLegacy(material);
         ItemStack[] inventory = getStorageContents();
         for (int i = 0; i < inventory.length; i++) {
@@ -257,7 +255,7 @@ public class CraftInventory implements Inventory {
     }
 
     public int firstPartial(Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         material = CraftLegacy.fromLegacy(material);
         ItemStack[] inventory = getStorageContents();
         for (int i = 0; i < inventory.length; i++) {
@@ -286,8 +284,8 @@ public class CraftInventory implements Inventory {
 
     @Override
     public HashMap<Integer, ItemStack> addItem(ItemStack... items) {
-        Validate.noNullElements(items, "Item cannot be null");
+        Preconditions.checkArgument(items != null, "items cannot be null");
-        HashMap<Integer, ItemStack> leftover = new HashMap<Integer, ItemStack>();
+        HashMap<Integer, ItemStack> leftover = new HashMap<>();
 
         /* TODO: some optimization
          *  - Create a 'firstPartial' with a 'fromIndex'
@@ -297,6 +295,7 @@ public class CraftInventory implements Inventory {
 
         for (int i = 0; i < items.length; i++) {
             ItemStack item = items[i];
+            Preconditions.checkArgument(item != null, "ItemStack cannot be null");
             while (true) {
                 // Do we already have a stack of it?
                 int firstPartial = firstPartial(item);
@@ -352,13 +351,14 @@ public class CraftInventory implements Inventory {
 
     @Override
     public HashMap<Integer, ItemStack> removeItem(ItemStack... items) {
-        Validate.notNull(items, "Items cannot be null");
+        Preconditions.checkArgument(items != null, "items cannot be null");
         HashMap<Integer, ItemStack> leftover = new HashMap<Integer, ItemStack>();
 
         // TODO: optimization
 
         for (int i = 0; i < items.length; i++) {
             ItemStack item = items[i];
+            Preconditions.checkArgument(item != null, "ItemStack cannot be null");
             int toDelete = item.getAmount();
 
             while (true) {
@@ -400,7 +400,7 @@ public class CraftInventory implements Inventory {
 
     @Override
     public void remove(Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         material = CraftLegacy.fromLegacy(material);
         ItemStack[] items = getStorageContents();
         for (int i = 0; i < items.length; i++) {

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryCrafting.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import java.util.Arrays;
 import java.util.List;
 import net.minecraft.world.IInventory;
@@ -31,9 +32,7 @@ public class CraftInventoryCrafting extends CraftInventory implements CraftingIn
 
     @Override
     public void setContents(ItemStack[] items) {
-        if (getSize() > items.length) {
+        Preconditions.checkArgument(getSize() <= items.length, "Invalid inventory size (%s); expected %s or less", items.length, getSize());
-            throw new IllegalArgumentException("Invalid inventory size; expected " + getSize() + " or less");
-        }
         setContents(items[0], Arrays.copyOfRange(items, 1, items.length));
     }
 
@@ -97,9 +96,7 @@ public class CraftInventoryCrafting extends CraftInventory implements CraftingIn
 
     @Override
     public void setMatrix(ItemStack[] contents) {
-        if (getMatrixInventory().getContainerSize() > contents.length) {
+        Preconditions.checkArgument(getMatrixInventory().getContainerSize() <= contents.length, "Invalid inventory size (%s); expected %s or less", contents.length, getMatrixInventory().getContainerSize());
-            throw new IllegalArgumentException("Invalid inventory size; expected " + getMatrixInventory().getContainerSize() + " or less");
-        }
 
         for (int i = 0; i < getMatrixInventory().getContainerSize(); i++) {
             if (i < contents.length) {

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryCustom.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
@@ -7,7 +8,6 @@ import net.minecraft.core.NonNullList;
 import net.minecraft.world.IInventory;
 import net.minecraft.world.entity.player.EntityHuman;
 import net.minecraft.world.item.ItemStack;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Location;
 import org.bukkit.craftbukkit.entity.CraftHumanEntity;
 import org.bukkit.entity.HumanEntity;
@@ -54,7 +54,7 @@ public class CraftInventoryCustom extends CraftInventory {
         }
 
         public MinecraftInventory(InventoryHolder owner, int size, String title) {
-            Validate.notNull(title, "Title cannot be null");
+            Preconditions.checkArgument(title != null, "title cannot be null");
             this.items = NonNullList.withSize(size, ItemStack.EMPTY);
             this.title = title;
             this.viewers = new ArrayList<HumanEntity>();

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryDoubleChest.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.world.ITileInventory;
 import net.minecraft.world.InventoryLargeChest;
 import net.minecraft.world.level.block.BlockChest;
@@ -47,9 +48,7 @@ public class CraftInventoryDoubleChest extends CraftInventory implements DoubleC
 
     @Override
     public void setContents(ItemStack[] items) {
-        if (getInventory().getContainerSize() < items.length) {
+        Preconditions.checkArgument(getInventory().getContainerSize() >= items.length, "Invalid inventory size (%s); expected %s or less", items.length, getInventory().getContainerSize());
-            throw new IllegalArgumentException("Invalid inventory size; expected " + getInventory().getContainerSize() + " or less");
-        }
         ItemStack[] leftItems = new ItemStack[left.getSize()], rightItems = new ItemStack[right.getSize()];
         System.arraycopy(items, 0, leftItems, 0, Math.min(left.getSize(), items.length));
         left.setContents(leftItems);

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryPlayer.java

@@ -5,7 +5,6 @@ import net.minecraft.network.protocol.game.PacketPlayOutHeldItemSlot;
 import net.minecraft.network.protocol.game.PacketPlayOutSetSlot;
 import net.minecraft.server.level.EntityPlayer;
 import net.minecraft.world.entity.player.PlayerInventory;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.inventory.EntityEquipment;
@@ -175,7 +174,7 @@ public class CraftInventoryPlayer extends CraftInventory implements org.bukkit.i
 
     @Override
     public void setHeldItemSlot(int slot) {
-        Validate.isTrue(slot >= 0 && slot < PlayerInventory.getSelectionSize(), "Slot is not between 0 and 8 inclusive");
+        Preconditions.checkArgument(slot >= 0 && slot < PlayerInventory.getSelectionSize(), "Slot (%s) is not between 0 and %s inclusive", slot, PlayerInventory.getSelectionSize() - 1);
         this.getInventory().selected = slot;
         ((CraftPlayer) this.getHolder()).getHandle().connection.send(new PacketPlayOutHeldItemSlot(slot));
     }
@@ -249,7 +248,7 @@ public class CraftInventoryPlayer extends CraftInventory implements org.bukkit.i
         if (items == null) {
             items = new ItemStack[length];
         }
-        Preconditions.checkArgument(items.length <= length, "items.length must be < %s", length);
+        Preconditions.checkArgument(items.length <= length, "items.length must be <= %s", length);
 
         for (int i = 0; i < length; i++) {
             if (i >= items.length) {

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemFactory.java

@@ -1,13 +1,12 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import com.mojang.brigadier.StringReader;
 import com.mojang.brigadier.exceptions.CommandSyntaxException;
 import net.minecraft.commands.arguments.item.ArgumentParserItemStack;
-import net.minecraft.core.HolderLookup;
 import net.minecraft.core.registries.BuiltInRegistries;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.world.item.Item;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Color;
 import org.bukkit.Material;
 import org.bukkit.configuration.serialization.ConfigurationSerialization;
@@ -42,16 +41,15 @@ public final class CraftItemFactory implements ItemFactory {
         if (type == null || meta == null) {
             return false;
         }
-        if (!(meta instanceof CraftMetaItem)) {
+
-            throw new IllegalArgumentException("Meta of " + meta.getClass().toString() + " not created by " + CraftItemFactory.class.getName());
+        Preconditions.checkArgument(meta instanceof CraftMetaItem, "Meta of %s not created by %s", meta.getClass().toString(), CraftItemFactory.class.getName());
-        }
 
         return ((CraftMetaItem) meta).applicableTo(type);
     }
 
     @Override
     public ItemMeta getItemMeta(Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
         return getItemMeta(material, null);
     }
 
@@ -366,16 +364,15 @@ public final class CraftItemFactory implements ItemFactory {
         if (meta1 == meta2) {
             return true;
         }
-        if (meta1 != null && !(meta1 instanceof CraftMetaItem)) {
+
-            throw new IllegalArgumentException("First meta of " + meta1.getClass().getName() + " does not belong to " + CraftItemFactory.class.getName());
+        if (meta1 != null) {
-        }
+            Preconditions.checkArgument(meta1 instanceof CraftMetaItem, "First meta of %s does not belong to %s", meta1.getClass().getName(), CraftItemFactory.class.getName());
-        if (meta2 != null && !(meta2 instanceof CraftMetaItem)) {
+        } else {
-            throw new IllegalArgumentException("Second meta " + meta2.getClass().getName() + " does not belong to " + CraftItemFactory.class.getName());
-        }
-        if (meta1 == null) {
             return ((CraftMetaItem) meta2).isEmpty();
         }
-        if (meta2 == null) {
+        if (meta2 != null) {
+            Preconditions.checkArgument(meta2 instanceof CraftMetaItem, "Second meta of %s does not belong to %s", meta2.getClass().getName(), CraftItemFactory.class.getName());
+        } else {
             return ((CraftMetaItem) meta1).isEmpty();
         }
 
@@ -401,16 +398,14 @@ public final class CraftItemFactory implements ItemFactory {
 
     @Override
     public ItemMeta asMetaFor(ItemMeta meta, ItemStack stack) {
-        Validate.notNull(stack, "Stack cannot be null");
+        Preconditions.checkArgument(stack != null, "ItemStack stack cannot be null");
         return asMetaFor(meta, stack.getType());
     }
 
     @Override
     public ItemMeta asMetaFor(ItemMeta meta, Material material) {
-        Validate.notNull(material, "Material cannot be null");
+        Preconditions.checkArgument(material != null, "Material cannot be null");
-        if (!(meta instanceof CraftMetaItem)) {
+        Preconditions.checkArgument(meta instanceof CraftMetaItem, "ItemMeta of %s not created by %s", (meta != null ? meta.getClass().toString() : "null"), CraftItemFactory.class.getName());
-            throw new IllegalArgumentException("Meta of " + (meta != null ? meta.getClass().toString() : "null") + " not created by " + CraftItemFactory.class.getName());
-        }
         return getItemMeta(material, (CraftMetaItem) meta);
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java

@@ -1,13 +1,13 @@
 package org.bukkit.craftbukkit.inventory;
 
 import static org.bukkit.craftbukkit.inventory.CraftMetaItem.*;
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import java.util.Map;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.enchantment.EnchantmentManager;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.NamespacedKey;
 import org.bukkit.configuration.serialization.DelegateDeserialization;
@@ -176,7 +176,7 @@ public final class CraftItemStack extends ItemStack {
 
     @Override
     public void addUnsafeEnchantment(Enchantment ench, int level) {
-        Validate.notNull(ench, "Cannot add null enchantment");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
 
         if (!makeTag(handle)) {
             return;
@@ -221,7 +221,7 @@ public final class CraftItemStack extends ItemStack {
 
     @Override
     public int getEnchantmentLevel(Enchantment ench) {
-        Validate.notNull(ench, "Cannot find null enchantment");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
         if (handle == null) {
             return 0;
         }
@@ -230,7 +230,7 @@ public final class CraftItemStack extends ItemStack {
 
     @Override
     public int removeEnchantment(Enchantment ench) {
-        Validate.notNull(ench, "Cannot remove null enchantment");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
 
         NBTTagList list = getEnchantmentList(handle), listCopy;
         if (list == null) {

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMerchantCustom.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.network.chat.IChatBaseComponent;
 import net.minecraft.sounds.SoundEffect;
 import net.minecraft.sounds.SoundEffects;
@@ -8,8 +9,6 @@ import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.trading.IMerchant;
 import net.minecraft.world.item.trading.MerchantRecipe;
 import net.minecraft.world.item.trading.MerchantRecipeList;
-import net.minecraft.world.level.World;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.util.CraftChatMessage;
 
 public class CraftMerchantCustom extends CraftMerchant {
@@ -37,7 +36,7 @@ public class CraftMerchantCustom extends CraftMerchant {
         protected CraftMerchant craftMerchant;
 
         public MinecraftMerchant(String title) {
-            Validate.notNull(title, "Title cannot be null");
+            Preconditions.checkArgument(title != null, "Title cannot be null");
             this.title = CraftChatMessage.fromString(title)[0];
         }
 

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBanner.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Sets;
@@ -114,9 +115,7 @@ public class CraftMetaBanner extends CraftMetaItem implements BannerMeta {
         }
 
         for (Object obj : rawPatternList) {
-            if (!(obj instanceof Pattern)) {
+            Preconditions.checkArgument(obj instanceof Pattern, "Object (%s) in pattern list is not valid", obj.getClass());
-                throw new IllegalArgumentException("Object in pattern list is not valid. " + obj.getClass());
-            }
             addPattern((Pattern) obj);
         }
     }

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBlockState.java

@@ -1,13 +1,13 @@
 package org.bukkit.craftbukkit.inventory;
 
 import com.google.common.base.Objects;
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Sets;
 import java.util.Map;
 import java.util.Set;
 import net.minecraft.nbt.NBTBase;
 import net.minecraft.nbt.NBTTagCompound;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.block.BlockState;
 import org.bukkit.configuration.serialization.DelegateDeserialization;
@@ -274,11 +274,11 @@ public class CraftMetaBlockState extends CraftMetaItem implements BlockStateMeta
 
     @Override
     public void setBlockState(BlockState blockState) {
-        Validate.notNull(blockState, "blockState must not be null");
+        Preconditions.checkArgument(blockState != null, "blockState must not be null");
 
         Material stateMaterial = (material != Material.SHIELD) ? material : shieldToBannerHack(blockEntityTag);
         Class<?> blockStateType = CraftBlockStates.getBlockStateType(stateMaterial);
-        Validate.isTrue(blockStateType == blockState.getClass() && blockState instanceof CraftBlockEntityState, "Invalid blockState for " + material);
+        Preconditions.checkArgument(blockStateType == blockState.getClass() && blockState instanceof CraftBlockEntityState, "Invalid blockState for " + material);
 
         blockEntityTag = ((CraftBlockEntityState) blockState).getSnapshotNBT();
         // Set shield base

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBook.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap.Builder;
 import com.google.common.collect.Lists;
@@ -12,7 +13,6 @@ import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
 import net.minecraft.nbt.NBTTagString;
 import net.minecraft.network.chat.IChatBaseComponent;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.configuration.serialization.DelegateDeserialization;
 import org.bukkit.craftbukkit.inventory.CraftMetaItem.SerializableMeta;
@@ -256,16 +256,14 @@ public class CraftMetaBook extends CraftMetaItem implements BookMeta {
 
     @Override
     public String getPage(final int page) {
-        Validate.isTrue(isValidPage(page), "Invalid page number");
+        Preconditions.checkArgument(isValidPage(page), "Invalid page number (%s)", page);
         // assert: pages != null
         return convertDataToPlainPage(pages.get(page - 1));
     }
 
     @Override
     public void setPage(final int page, final String text) {
-        if (!isValidPage(page)) {
+        Preconditions.checkArgument(isValidPage(page), "Invalid page number (%s/%s)", page, getPageCount());
-            throw new IllegalArgumentException("Invalid page number " + page + "/" + getPageCount());
-        }
         // assert: pages != null
 
         String newText = validatePage(text);
@@ -379,8 +377,7 @@ public class CraftMetaBook extends CraftMetaItem implements BookMeta {
         if (!super.equalsCommon(meta)) {
             return false;
         }
-        if (meta instanceof CraftMetaBook) {
+        if (meta instanceof CraftMetaBook that) {
-            CraftMetaBook that = (CraftMetaBook) meta;
 
             return (hasTitle() ? that.hasTitle() && this.title.equals(that.title) : !that.hasTitle())
                     && (hasAuthor() ? that.hasAuthor() && this.author.equals(that.author) : !that.hasAuthor())

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaFirework.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap.Builder;
 import java.util.ArrayList;
@@ -8,7 +9,6 @@ import java.util.List;
 import java.util.Map;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Color;
 import org.bukkit.FireworkEffect;
 import org.bukkit.FireworkEffect.Type;
@@ -58,16 +58,14 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
     CraftMetaFirework(CraftMetaItem meta) {
         super(meta);
 
-        if (!(meta instanceof CraftMetaFirework)) {
+        if (!(meta instanceof CraftMetaFirework that)) {
             return;
         }
 
-        CraftMetaFirework that = (CraftMetaFirework) meta;
-
         this.power = that.power;
 
         if (that.hasEffects()) {
-            this.effects = new ArrayList<FireworkEffect>(that.effects);
+            this.effects = new ArrayList<>(that.effects);
         }
     }
 
@@ -200,15 +198,12 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
 
         List<FireworkEffect> effects = this.effects;
         if (effects == null) {
-            effects = this.effects = new ArrayList<FireworkEffect>();
+            effects = this.effects = new ArrayList<>();
         }
 
         for (Object obj : collection) {
-            if (obj instanceof FireworkEffect) {
+            Preconditions.checkArgument(obj instanceof FireworkEffect, "%s in %s is not a FireworkEffect", obj, collection);
             effects.add((FireworkEffect) obj);
-            } else {
-                throw new IllegalArgumentException(obj + " in " + collection + " is not a FireworkEffect");
-            }
         }
     }
 
@@ -276,8 +271,7 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
             return false;
         }
 
-        if (meta instanceof CraftMetaFirework) {
+        if (meta instanceof CraftMetaFirework that) {
-            CraftMetaFirework that = (CraftMetaFirework) meta;
 
             return (hasPower() ? that.hasPower() && this.power == that.power : !that.hasPower())
                     && (hasEffects() ? that.hasEffects() && this.effects.equals(that.effects) : !that.hasEffects());
@@ -332,7 +326,7 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
 
     @Override
     public void addEffect(FireworkEffect effect) {
-        Validate.notNull(effect, "Effect cannot be null");
+        Preconditions.checkArgument(effect != null, "FireworkEffect cannot be null");
         if (this.effects == null) {
             this.effects = new ArrayList<FireworkEffect>();
         }
@@ -341,7 +335,7 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
 
     @Override
     public void addEffects(FireworkEffect... effects) {
-        Validate.notNull(effects, "Effects cannot be null");
+        Preconditions.checkArgument(effects != null, "effects cannot be null");
         if (effects.length == 0) {
             return;
         }
@@ -352,14 +346,14 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
         }
 
         for (FireworkEffect effect : effects) {
-            Validate.notNull(effect, "Effect cannot be null");
+            Preconditions.checkArgument(effect != null, "effects cannot contain null FireworkEffect");
             list.add(effect);
         }
     }
 
     @Override
     public void addEffects(Iterable<FireworkEffect> effects) {
-        Validate.notNull(effects, "Effects cannot be null");
+        Preconditions.checkArgument(effects != null, "effects cannot be null");
         safelyAddEffects(effects);
     }
 
@@ -394,8 +388,8 @@ class CraftMetaFirework extends CraftMetaItem implements FireworkMeta {
 
     @Override
     public void setPower(int power) {
-        Validate.isTrue(power >= 0, "Power cannot be less than zero: ", power);
+        Preconditions.checkArgument(power >= 0, "power cannot be less than zero: %s", power);
-        Validate.isTrue(power < 0x80, "Power cannot be more than 127: ", power);
+        Preconditions.checkArgument(power < 0x80, "power cannot be more than 127: %s", power);
         this.power = power;
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java

@@ -46,7 +46,6 @@ import net.minecraft.network.chat.IChatBaseComponent;
 import net.minecraft.world.entity.EnumItemSlot;
 import net.minecraft.world.item.ItemBlock;
 import net.minecraft.world.level.block.state.IBlockData;
-import org.apache.commons.lang.Validate;
 import org.apache.commons.lang3.EnumUtils;
 import org.bukkit.Material;
 import org.bukkit.attribute.Attribute;
@@ -180,7 +179,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
         }
 
         public static ItemMeta deserialize(Map<String, Object> map) throws Throwable {
-            Validate.notNull(map, "Cannot deserialize null map");
+            Preconditions.checkArgument(map != null, "Cannot deserialize null map");
 
             String type = getString(map, TYPE_FIELD, false);
             Constructor<? extends CraftMetaItem> constructor = constructorMap.get(type);
@@ -789,13 +788,13 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
 
     @Override
     public boolean hasEnchant(Enchantment ench) {
-        Validate.notNull(ench, "Enchantment cannot be null");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
         return hasEnchants() && enchantments.containsKey(ench);
     }
 
     @Override
     public int getEnchantLevel(Enchantment ench) {
-        Validate.notNull(ench, "Enchantment cannot be null");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
         Integer level = hasEnchants() ? enchantments.get(ench) : null;
         if (level == null) {
             return 0;
@@ -810,7 +809,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
 
     @Override
     public boolean addEnchant(Enchantment ench, int level, boolean ignoreRestrictions) {
-        Validate.notNull(ench, "Enchantment cannot be null");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
         if (enchantments == null) {
             enchantments = new LinkedHashMap<Enchantment, Integer>(4);
         }
@@ -824,7 +823,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
 
     @Override
     public boolean removeEnchant(Enchantment ench) {
-        Validate.notNull(ench, "Enchantment cannot be null");
+        Preconditions.checkArgument(ench != null, "Enchantment cannot be null");
         return hasEnchants() && enchantments.remove(ench) != null;
     }
 
@@ -1330,9 +1329,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
 
         for (Object object : addFrom) {
             if (!(object instanceof String)) {
-                if (object != null) {
+                Preconditions.checkArgument(object == null, "%s cannot contain non-string %s", addFrom, object.getClass().getName());
-                    throw new IllegalArgumentException(addFrom + " cannot contain non-string " + object.getClass().getName());
-                }
 
                 addTo.add(CraftChatMessage.toJSON(IChatBaseComponent.empty()));
             } else {

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaPotion.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap.Builder;
 import com.google.common.collect.Sets;
@@ -10,7 +11,6 @@ import java.util.Map;
 import java.util.Set;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Color;
 import org.bukkit.Material;
 import org.bukkit.configuration.serialization.DelegateDeserialization;
@@ -51,14 +51,13 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
 
     CraftMetaPotion(CraftMetaItem meta) {
         super(meta);
-        if (!(meta instanceof CraftMetaPotion)) {
+        if (!(meta instanceof CraftMetaPotion potionMeta)) {
             return;
         }
-        CraftMetaPotion potionMeta = (CraftMetaPotion) meta;
         this.type = potionMeta.type;
         this.color = potionMeta.color;
         if (potionMeta.hasCustomEffects()) {
-            this.customEffects = new ArrayList<PotionEffect>(potionMeta.customEffects);
+            this.customEffects = new ArrayList<>(potionMeta.customEffects);
         }
     }
 
@@ -77,7 +76,7 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
         if (tag.contains(POTION_EFFECTS.NBT)) {
             NBTTagList list = tag.getList(POTION_EFFECTS.NBT, CraftMagicNumbers.NBT.TAG_COMPOUND);
             int length = list.size();
-            customEffects = new ArrayList<PotionEffect>(length);
+            customEffects = new ArrayList<>(length);
 
             for (int i = 0; i < length; i++) {
                 NBTTagCompound effect = list.getCompound(i);
@@ -112,9 +111,7 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
         }
 
         for (Object obj : rawEffectList) {
-            if (!(obj instanceof PotionEffect)) {
+            Preconditions.checkArgument(obj instanceof PotionEffect, "Object (%s) in effect list is not valid", obj.getClass());
-                throw new IllegalArgumentException("Object in effect list is not valid. " + obj.getClass());
-            }
             addCustomEffect((PotionEffect) obj, true);
         }
     }
@@ -165,14 +162,14 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
         CraftMetaPotion clone = (CraftMetaPotion) super.clone();
         clone.type = type;
         if (this.customEffects != null) {
-            clone.customEffects = new ArrayList<PotionEffect>(this.customEffects);
+            clone.customEffects = new ArrayList<>(this.customEffects);
         }
         return clone;
     }
 
     @Override
     public void setBasePotionData(PotionData data) {
-        Validate.notNull(data, "PotionData cannot be null");
+        Preconditions.checkArgument(data != null, "PotionData cannot be null");
         this.type = data;
     }
 
@@ -196,7 +193,7 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
 
     @Override
     public boolean addCustomEffect(PotionEffect effect, boolean overwrite) {
-        Validate.notNull(effect, "Potion effect must not be null");
+        Preconditions.checkArgument(effect != null, "Potion effect cannot be null");
 
         int index = indexOfEffect(effect.getType());
         if (index != -1) {
@@ -212,7 +209,7 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
             }
         } else {
             if (customEffects == null) {
-                customEffects = new ArrayList<PotionEffect>();
+                customEffects = new ArrayList<>();
             }
             customEffects.add(effect);
             return true;
@@ -221,7 +218,7 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
 
     @Override
     public boolean removeCustomEffect(PotionEffectType type) {
-        Validate.notNull(type, "Potion effect type must not be null");
+        Preconditions.checkArgument(type != null, "Potion effect type cannot be null");
 
         if (!hasCustomEffects()) {
             return false;
@@ -244,13 +241,13 @@ class CraftMetaPotion extends CraftMetaItem implements PotionMeta {
 
     @Override
     public boolean hasCustomEffect(PotionEffectType type) {
-        Validate.notNull(type, "Potion effect type must not be null");
+        Preconditions.checkArgument(type != null, "Potion effect type cannot be null");
         return indexOfEffect(type) != -1;
     }
 
     @Override
     public boolean setMainEffect(PotionEffectType type) {
-        Validate.notNull(type, "Potion effect type must not be null");
+        Preconditions.checkArgument(type != null, "Potion effect type cannot be null");
         int index = indexOfEffect(type);
         if (index == -1 || index == 0) {
             return false;

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaSuspiciousStew.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap.Builder;
 import java.util.ArrayList;
@@ -8,11 +9,8 @@ import java.util.List;
 import java.util.Map;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.configuration.serialization.DelegateDeserialization;
-import org.bukkit.craftbukkit.inventory.CraftMetaItem.ItemMetaKey;
-import org.bukkit.craftbukkit.inventory.CraftMetaItem.SerializableMeta;
 import org.bukkit.craftbukkit.util.CraftMagicNumbers;
 import org.bukkit.inventory.meta.SuspiciousStewMeta;
 import org.bukkit.potion.PotionEffect;
@@ -29,12 +27,11 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
 
     CraftMetaSuspiciousStew(CraftMetaItem meta) {
         super(meta);
-        if (!(meta instanceof CraftMetaSuspiciousStew)) {
+        if (!(meta instanceof CraftMetaSuspiciousStew stewMeta)) {
             return;
         }
-        CraftMetaSuspiciousStew stewMeta = ((CraftMetaSuspiciousStew) meta);
         if (stewMeta.hasCustomEffects()) {
-            this.customEffects = new ArrayList<PotionEffect>(stewMeta.customEffects);
+            this.customEffects = new ArrayList<>(stewMeta.customEffects);
         }
     }
 
@@ -43,7 +40,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
         if (tag.contains(EFFECTS.NBT)) {
             NBTTagList list = tag.getList(EFFECTS.NBT, CraftMagicNumbers.NBT.TAG_COMPOUND);
             int length = list.size();
-            customEffects = new ArrayList<PotionEffect>(length);
+            customEffects = new ArrayList<>(length);
 
             for (int i = 0; i < length; i++) {
                 NBTTagCompound effect = list.getCompound(i);
@@ -66,9 +63,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
         }
 
         for (Object obj : rawEffectList) {
-            if (!(obj instanceof PotionEffect)) {
+            Preconditions.checkArgument(obj instanceof PotionEffect, "Object (%s) in effect list is not valid", obj.getClass());
-                throw new IllegalArgumentException("Object in effect list is not valid. " + obj.getClass());
-            }
             addCustomEffect((PotionEffect) obj, true);
         }
     }
@@ -108,7 +103,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
     public CraftMetaSuspiciousStew clone() {
         CraftMetaSuspiciousStew clone = ((CraftMetaSuspiciousStew) super.clone());
         if (this.customEffects != null) {
-            clone.customEffects = new ArrayList<PotionEffect>(this.customEffects);
+            clone.customEffects = new ArrayList<>(this.customEffects);
         }
         return clone;
     }
@@ -128,7 +123,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
 
     @Override
     public boolean addCustomEffect(PotionEffect effect, boolean overwrite) {
-        Validate.notNull(effect, "Potion effect must not be null");
+        Preconditions.checkArgument(effect != null, "Potion effect cannot be null");
 
         int index = indexOfEffect(effect.getType());
         if (index != -1) {
@@ -144,7 +139,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
             }
         } else {
             if (customEffects == null) {
-                customEffects = new ArrayList<PotionEffect>();
+                customEffects = new ArrayList<>();
             }
             customEffects.add(effect);
             return true;
@@ -153,7 +148,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
 
     @Override
     public boolean removeCustomEffect(PotionEffectType type) {
-        Validate.notNull(type, "Potion effect type must not be null");
+        Preconditions.checkArgument(type != null, "Potion effect type cannot be null");
 
         if (!hasCustomEffects()) {
             return false;
@@ -176,7 +171,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
 
     @Override
     public boolean hasCustomEffect(PotionEffectType type) {
-        Validate.notNull(type, "Potion effect type must not be null");
+        Preconditions.checkArgument(type != null, "Potion effect type cannot be null");
         return indexOfEffect(type) != -1;
     }
 
@@ -215,9 +210,7 @@ public class CraftMetaSuspiciousStew extends CraftMetaItem implements Suspicious
         if (!super.equalsCommon(meta)) {
             return false;
         }
-        if (meta instanceof CraftMetaSuspiciousStew) {
+        if (meta instanceof CraftMetaSuspiciousStew that) {
-            CraftMetaSuspiciousStew that = (CraftMetaSuspiciousStew) meta;
-
             return (this.hasCustomEffects() ? that.hasCustomEffects() && this.customEffects.equals(that.customEffects) : !that.hasCustomEffects());
         }
         return true;

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftRecipe.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import java.util.ArrayList;
 import java.util.List;
 import net.minecraft.world.item.crafting.RecipeItemStack;
@@ -29,8 +30,8 @@ public interface CraftRecipe extends Recipe {
         }
 
         stack.getItems();
-        if (requireNotEmpty && stack.itemStacks.length == 0) {
+        if (requireNotEmpty) {
-            throw new IllegalArgumentException("Recipe requires at least one non-air choice!");
+            Preconditions.checkArgument(stack.itemStacks.length != 0, "Recipe requires at least one non-air choice");
         }
 
         return stack;

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/InventoryIterator.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import java.util.ListIterator;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
@@ -53,9 +54,7 @@ public class InventoryIterator implements ListIterator<ItemStack> {
 
     @Override
     public void set(ItemStack item) {
-        if (lastDirection == null) {
+        Preconditions.checkState(lastDirection != null, "No current item!");
-            throw new IllegalStateException("No current item!");
-        }
         int i = lastDirection ? nextIndex - 1 : nextIndex;
         inventory.setItem(i, item);
     }

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/RecipeIterator.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.inventory;
 
+import com.google.common.base.Preconditions;
 import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap;
 import java.util.Iterator;
 import java.util.Map;
@@ -43,10 +44,7 @@ public class RecipeIterator implements Iterator<Recipe> {
 
     @Override
     public void remove() {
-        if (current == null) {
+        Preconditions.checkState(current != null, "next() not yet called");
-            throw new IllegalStateException("next() not yet called");
-        }
-
         current.remove();
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/tags/DeprecatedContainerTagType.java

@@ -1,6 +1,6 @@
 package org.bukkit.craftbukkit.inventory.tags;
 
-import org.apache.commons.lang3.Validate;
+import com.google.common.base.Preconditions;
 import org.bukkit.craftbukkit.persistence.CraftPersistentDataContainer;
 import org.bukkit.inventory.meta.tags.CustomItemTagContainer;
 import org.bukkit.inventory.meta.tags.ItemTagType;
@@ -29,11 +29,11 @@ public final class DeprecatedContainerTagType<Z> implements PersistentDataType<P
     @Override
     public PersistentDataContainer toPrimitive(Z complex, PersistentDataAdapterContext context) {
         CustomItemTagContainer deprecated = this.deprecated.toPrimitive(complex, new DeprecatedItemAdapterContext(context));
-        Validate.isInstanceOf(DeprecatedCustomTagContainer.class, deprecated, "Could not wrap deprecated API due to foreign CustomItemTagContainer implementation %s", deprecated.getClass().getSimpleName());
+        Preconditions.checkArgument(deprecated instanceof DeprecatedCustomTagContainer, "Could not wrap deprecated API due to foreign CustomItemTagContainer implementation %s", deprecated.getClass().getSimpleName());
 
         DeprecatedCustomTagContainer tagContainer = (DeprecatedCustomTagContainer) deprecated;
         PersistentDataContainer wrapped = tagContainer.getWrapped();
-        Validate.isInstanceOf(CraftPersistentDataContainer.class, wrapped, "Could not wrap deprecated API due to wrong deprecation wrapper %s", deprecated.getClass().getSimpleName());
+        Preconditions.checkArgument(wrapped instanceof CraftPersistentDataContainer, "Could not wrap deprecated API due to wrong deprecation wrapper %s", deprecated.getClass().getSimpleName());
 
         CraftPersistentDataContainer craftTagContainer = (CraftPersistentDataContainer) wrapped;
         return new CraftPersistentDataContainer(craftTagContainer.getRaw(), craftTagContainer.getDataTagTypeRegistry());
@@ -41,7 +41,7 @@ public final class DeprecatedContainerTagType<Z> implements PersistentDataType<P
 
     @Override
     public Z fromPrimitive(PersistentDataContainer primitive, PersistentDataAdapterContext context) {
-        Validate.isInstanceOf(CraftPersistentDataContainer.class, primitive, "Could not wrap deprecated API due to foreign PersistentMetadataContainer implementation %s", primitive.getClass().getSimpleName());
+        Preconditions.checkArgument(primitive instanceof CraftPersistentDataContainer, "Could not wrap deprecated API due to foreign PersistentMetadataContainer implementation %s", primitive.getClass().getSimpleName());
 
         return this.deprecated.fromPrimitive(new DeprecatedCustomTagContainer(primitive), new DeprecatedItemAdapterContext(context));
     }

paper-server/src/main/java/org/bukkit/craftbukkit/legacy/CraftLegacy.java

@@ -348,17 +348,13 @@ public final class CraftLegacy {
                             IBlockState state = states.getProperty(dataKey);
 
                             if (state == null) {
-                                if (whitelistedStates.contains(dataKey)) {
+                                Preconditions.checkArgument(whitelistedStates.contains(dataKey), "No state for %s", dataKey);
                                 continue;
                             }
-                                throw new IllegalStateException("No state for " + dataKey);
-                            }
 
                             Preconditions.checkState(!properties.getString(dataKey).isEmpty(), "Empty data string");
                             Optional opt = state.getValue(properties.getString(dataKey));
-                            if (!opt.isPresent()) {
+                            Preconditions.checkArgument(opt.isPresent(), "No state value %s for %s", properties.getString(dataKey), dataKey);
-                                throw new IllegalStateException("No state value " + properties.getString(dataKey) + " for " + dataKey);
-                            }
 
                             blockData = blockData.setValue(state, (Comparable) opt.get());
                         }

paper-server/src/main/java/org/bukkit/craftbukkit/map/CraftMapCanvas.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.map;
 
+import com.google.common.base.Preconditions;
 import java.awt.Color;
 import java.awt.Image;
 import java.util.Arrays;
@@ -102,9 +103,7 @@ public class CraftMapCanvas implements MapCanvas {
     public void drawText(int x, int y, MapFont font, String text) {
         int xStart = x;
         byte color = MapPalette.DARK_GRAY;
-        if (!font.isValid(text)) {
+        Preconditions.checkArgument(font.isValid(text), "text (%s) contains invalid characters", text);
-            throw new IllegalArgumentException("text contains invalid characters");
-        }
 
         for (int i = 0; i < text.length(); ++i) {
             char ch = text.charAt(i);
@@ -114,7 +113,7 @@ public class CraftMapCanvas implements MapCanvas {
                 continue;
             } else if (ch == '\u00A7') {
                 int j = text.indexOf(';', i);
-                if (j >= 0) {
+                Preconditions.checkArgument(j >= 0, "text (%s) unterminated color string", text);
                 try {
                     color = Byte.parseByte(text.substring(i + 1, j));
                     i = j;
@@ -122,8 +121,6 @@ public class CraftMapCanvas implements MapCanvas {
                 } catch (NumberFormatException ex) {
                 }
             }
-                throw new IllegalArgumentException("Text contains unterminated color string");
-            }
 
             CharacterSprite sprite = font.getChar(text.charAt(i));
             for (int r = 0; r < font.getHeight(); ++r) {

paper-server/src/main/java/org/bukkit/craftbukkit/map/CraftMapView.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.map;
 
+import com.google.common.base.Preconditions;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -16,7 +17,6 @@ import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.bukkit.map.MapRenderer;
 import org.bukkit.map.MapView;
-import org.bukkit.map.MapView.Scale;
 
 public final class CraftMapView implements MapView {
 
@@ -33,15 +33,12 @@ public final class CraftMapView implements MapView {
     @Override
     public int getId() {
         String text = worldMap.id;
-        if (text.startsWith("map_")) {
+        Preconditions.checkState(text.startsWith("map_"), "Map has a invalid ID");
         try {
             return Integer.parseInt(text.substring("map_".length()));
         } catch (NumberFormatException ex) {
             throw new IllegalStateException("Map has non-numeric ID");
         }
-        } else {
-            throw new IllegalStateException("Map has invalid ID");
-        }
     }
 
     @Override

paper-server/src/main/java/org/bukkit/craftbukkit/metadata/BlockMetadataStore.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.metadata;
 
+import com.google.common.base.Preconditions;
 import java.util.List;
 import org.bukkit.World;
 import org.bukkit.block.Block;
@@ -42,11 +43,8 @@ public class BlockMetadataStore extends MetadataStoreBase<Block> implements Meta
      */
     @Override
     public List<MetadataValue> getMetadata(Block block, String metadataKey) {
-        if (block.getWorld() == owningWorld) {
+        Preconditions.checkArgument(block.getWorld() == this.owningWorld, "Block does not belong to world %s", owningWorld.getName());
         return super.getMetadata(block, metadataKey);
-        } else {
-            throw new IllegalArgumentException("Block does not belong to world " + owningWorld.getName());
-        }
     }
 
     /**
@@ -56,11 +54,8 @@ public class BlockMetadataStore extends MetadataStoreBase<Block> implements Meta
      */
     @Override
     public boolean hasMetadata(Block block, String metadataKey) {
-        if (block.getWorld() == owningWorld) {
+        Preconditions.checkArgument(block.getWorld() == this.owningWorld, "Block does not belong to world %s", owningWorld.getName());
         return super.hasMetadata(block, metadataKey);
-        } else {
-            throw new IllegalArgumentException("Block does not belong to world " + owningWorld.getName());
-        }
     }
 
     /**
@@ -70,11 +65,8 @@ public class BlockMetadataStore extends MetadataStoreBase<Block> implements Meta
      */
     @Override
     public void removeMetadata(Block block, String metadataKey, Plugin owningPlugin) {
-        if (block.getWorld() == owningWorld) {
+        Preconditions.checkArgument(block.getWorld() == this.owningWorld, "Block does not belong to world %s", owningWorld.getName());
         super.removeMetadata(block, metadataKey, owningPlugin);
-        } else {
-            throw new IllegalArgumentException("Block does not belong to world " + owningWorld.getName());
-        }
     }
 
     /**
@@ -84,10 +76,7 @@ public class BlockMetadataStore extends MetadataStoreBase<Block> implements Meta
      */
     @Override
     public void setMetadata(Block block, String metadataKey, MetadataValue newMetadataValue) {
-        if (block.getWorld() == owningWorld) {
+        Preconditions.checkArgument(block.getWorld() == this.owningWorld, "Block does not belong to world %s", owningWorld.getName());
         super.setMetadata(block, metadataKey, newMetadataValue);
-        } else {
-            throw new IllegalArgumentException("Block does not belong to world " + owningWorld.getName());
-        }
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.persistence;
 
+import com.google.common.base.Preconditions;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -8,7 +9,6 @@ import java.util.Objects;
 import java.util.Set;
 import net.minecraft.nbt.NBTBase;
 import net.minecraft.nbt.NBTTagCompound;
-import org.apache.commons.lang.Validate;
 import org.bukkit.NamespacedKey;
 import org.bukkit.craftbukkit.util.CraftNBTTagConfigSerializer;
 import org.bukkit.persistence.PersistentDataAdapterContext;
@@ -34,17 +34,17 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
 
     @Override
     public <T, Z> void set(NamespacedKey key, PersistentDataType<T, Z> type, Z value) {
-        Validate.notNull(key, "The provided key for the custom value was null");
+        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
-        Validate.notNull(type, "The provided type for the custom value was null");
+        Preconditions.checkArgument(type != null, "The provided type cannot be null");
-        Validate.notNull(value, "The provided value for the custom value was null");
+        Preconditions.checkArgument(value != null, "The provided value cannot be null");
 
         this.customDataTags.put(key.toString(), registry.wrap(type.getPrimitiveType(), type.toPrimitive(value, adapterContext)));
     }
 
     @Override
     public <T, Z> boolean has(NamespacedKey key, PersistentDataType<T, Z> type) {
-        Validate.notNull(key, "The provided key for the custom value was null");
+        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
-        Validate.notNull(type, "The provided type for the custom value was null");
+        Preconditions.checkArgument(type != null, "The provided type cannot be null");
 
         NBTBase value = this.customDataTags.get(key.toString());
         if (value == null) {
@@ -56,8 +56,8 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
 
     @Override
     public <T, Z> Z get(NamespacedKey key, PersistentDataType<T, Z> type) {
-        Validate.notNull(key, "The provided key for the custom value was null");
+        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
-        Validate.notNull(type, "The provided type for the custom value was null");
+        Preconditions.checkArgument(type != null, "The provided type cannot be null");
 
         NBTBase value = this.customDataTags.get(key.toString());
         if (value == null) {
@@ -89,7 +89,7 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
 
     @Override
     public void remove(NamespacedKey key) {
-        Validate.notNull(key, "The provided key for the custom value was null");
+        Preconditions.checkArgument(key != null, "The NamespacedKey key cannot be null");
 
         this.customDataTags.remove(key.toString());
     }

paper-server/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataTypeRegistry.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.persistence;
 
+import com.google.common.base.Preconditions;
 import com.google.common.primitives.Primitives;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -56,9 +57,7 @@ public final class CraftPersistentDataTypeRegistry {
          * extractor function
          */
         T extract(NBTBase base) {
-            if (!nbtBaseType.isInstance(base)) {
+            Preconditions.checkArgument(nbtBaseType.isInstance(base), "The provided NBTBase was of the type %s. Expected type %s", base.getClass().getSimpleName(), nbtBaseType.getSimpleName());
-                throw new IllegalArgumentException(String.format("The provided NBTBase was of the type %s. Expected type %s", base.getClass().getSimpleName(), nbtBaseType.getSimpleName()));
-            }
             return this.extractor.apply(nbtBaseType.cast(base));
         }
 
@@ -74,9 +73,7 @@ public final class CraftPersistentDataTypeRegistry {
          * function
          */
         Z build(Object value) {
-            if (!primitiveType.isInstance(value)) {
+            Preconditions.checkArgument(primitiveType.isInstance(value), "The provided value was of the type %s. Expected type %s", value.getClass().getSimpleName(), primitiveType.getSimpleName());
-                throw new IllegalArgumentException(String.format("The provided value was of the type %s. Expected type %s", value.getClass().getSimpleName(), primitiveType.getSimpleName()));
-            }
             return this.builder.apply(primitiveType.cast(value));
         }
 
@@ -250,14 +247,10 @@ public final class CraftPersistentDataTypeRegistry {
      */
     public <T> T extract(Class<T> type, NBTBase tag) throws ClassCastException, IllegalArgumentException {
         TagAdapter adapter = this.adapters.computeIfAbsent(type, CREATE_ADAPTER);
-        if (!adapter.isInstance(tag)) {
+        Preconditions.checkArgument(adapter.isInstance(tag), "The found tag instance (%s) cannot store %s", tag.getClass().getSimpleName(), type.getSimpleName());
-            throw new IllegalArgumentException(String.format("`The found tag instance cannot store %s as it is a %s", type.getSimpleName(), tag.getClass().getSimpleName()));
-        }
 
         Object foundValue = adapter.extract(tag);
-        if (!type.isInstance(foundValue)) {
+        Preconditions.checkArgument(type.isInstance(foundValue), "The found object is of the type %s. Expected type %s", foundValue.getClass().getSimpleName(), type.getSimpleName());
-            throw new IllegalArgumentException(String.format("The found object is of the type %s. Expected type %s", foundValue.getClass().getSimpleName(), type.getSimpleName()));
-        }
         return type.cast(foundValue);
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/profile/CraftPlayerProfile.java

@@ -263,9 +263,7 @@ public final class CraftPlayerProfile implements PlayerProfile {
 
         if (map.containsKey("properties")) {
             for (Object propertyData : (List<?>) map.get("properties")) {
-                if (!(propertyData instanceof Map)) {
+                Preconditions.checkArgument(propertyData instanceof Map, "Propertu data (%s) is not a valid Map", propertyData);
-                    throw new IllegalArgumentException("Property data (" + propertyData + ") is not a valid Map");
-                }
                 Property property = CraftProfileProperty.deserialize((Map<?, ?>) propertyData);
                 profile.properties.put(property.getName(), property);
             }

paper-server/src/main/java/org/bukkit/craftbukkit/projectiles/CraftBlockProjectileSource.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.projectiles;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.core.EnumDirection;
 import net.minecraft.core.IPosition;
 import net.minecraft.core.SourceBlock;
@@ -20,7 +21,6 @@ import net.minecraft.world.entity.projectile.EntityTippedArrow;
 import net.minecraft.world.entity.projectile.IProjectile;
 import net.minecraft.world.level.block.BlockDispenser;
 import net.minecraft.world.level.block.entity.TileEntityDispenser;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
@@ -63,7 +63,7 @@ public class CraftBlockProjectileSource implements BlockProjectileSource {
 
     @Override
     public <T extends Projectile> T launchProjectile(Class<? extends T> projectile, Vector velocity) {
-        Validate.isTrue(getBlock().getType() == Material.DISPENSER, "Block is no longer dispenser");
+        Preconditions.checkArgument(getBlock().getType() == Material.DISPENSER, "Block is no longer dispenser");
         // Copied from BlockDispenser.dispense()
         SourceBlock isourceblock = new SourceBlock((WorldServer) dispenserBlock.getLevel(), dispenserBlock.getBlockPos());
         // Copied from DispenseBehaviorProjectile
@@ -132,7 +132,7 @@ public class CraftBlockProjectileSource implements BlockProjectileSource {
             ((EntityFireball) launch).projectileSource = this;
         }
 
-        Validate.notNull(launch, "Projectile not supported");
+        Preconditions.checkArgument(launch != null, "Projectile not supported");
 
         if (launch instanceof IProjectile) {
             if (launch instanceof EntityProjectile) {

paper-server/src/main/java/org/bukkit/craftbukkit/scheduler/CraftScheduler.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.scheduler;
 
+import com.google.common.base.Preconditions;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -16,7 +17,6 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.IntUnaryOperator;
 import java.util.logging.Level;
-import org.apache.commons.lang.Validate;
 import org.bukkit.plugin.IllegalPluginAccessException;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.scheduler.BukkitRunnable;
@@ -283,7 +283,7 @@ public class CraftScheduler implements BukkitScheduler {
 
     @Override
     public void cancelTasks(final Plugin plugin) {
-        Validate.notNull(plugin, "Cannot cancel tasks of null plugin");
+        Preconditions.checkArgument(plugin != null, "Cannot cancel tasks of null plugin");
         final CraftTask task = new CraftTask(
                 new Runnable() {
                     @Override
@@ -459,16 +459,15 @@ public class CraftScheduler implements BukkitScheduler {
     }
 
     private static void validate(final Plugin plugin, final Object task) {
-        Validate.notNull(plugin, "Plugin cannot be null");
+        Preconditions.checkArgument(plugin != null, "Plugin cannot be null");
-        Validate.notNull(task, "Task cannot be null");
+        Preconditions.checkArgument(task instanceof Runnable || task instanceof Consumer || task instanceof Callable, "Task must be Runnable, Consumer, or Callable");
-        Validate.isTrue(task instanceof Runnable || task instanceof Consumer || task instanceof Callable, "Task must be Runnable, Consumer, or Callable");
         if (!plugin.isEnabled()) {
             throw new IllegalPluginAccessException("Plugin attempted to register task while disabled");
         }
     }
 
     private int nextId() {
-        Validate.isTrue(runners.size() < Integer.MAX_VALUE, "There are already " + Integer.MAX_VALUE + " tasks scheduled! Cannot schedule more.");
+        Preconditions.checkArgument(runners.size() < Integer.MAX_VALUE, "There are already %s tasks scheduled! Cannot schedule more", Integer.MAX_VALUE);
         int id;
         do {
             id = ids.updateAndGet(INCREMENT_IDS);

paper-server/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftObjective.java

@@ -1,8 +1,8 @@
 package org.bukkit.craftbukkit.scoreboard;
 
+import com.google.common.base.Preconditions;
 import net.minecraft.world.scores.Scoreboard;
 import net.minecraft.world.scores.ScoreboardObjective;
-import org.apache.commons.lang.Validate;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.craftbukkit.util.CraftChatMessage;
 import org.bukkit.scoreboard.Criteria;
@@ -27,44 +27,44 @@ final class CraftObjective extends CraftScoreboardComponent implements Objective
 
     @Override
     public String getName() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return objective.getName();
     }
 
     @Override
     public String getDisplayName() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return CraftChatMessage.fromComponent(objective.getDisplayName());
     }
 
     @Override
     public void setDisplayName(String displayName) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(displayName, "Display name cannot be null");
+        Preconditions.checkArgument(displayName != null, "Display name cannot be null");
-        Validate.isTrue(displayName.length() <= 128, "Display name '" + displayName + "' is longer than the limit of 128 characters");
+        Preconditions.checkArgument(displayName.length() <= 128, "Display name '" + displayName + "' is longer than the limit of 128 characters");
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         objective.setDisplayName(CraftChatMessage.fromString(displayName)[0]); // SPIGOT-4112: not nullable
     }
 
     @Override
     public String getCriteria() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return criteria.bukkitName;
     }
 
     @Override
     public Criteria getTrackedCriteria() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return criteria;
     }
 
     @Override
     public boolean isModifiable() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return !criteria.criteria.isReadOnly();
     }
@@ -102,32 +102,32 @@ final class CraftObjective extends CraftScoreboardComponent implements Objective
 
     @Override
     public void setRenderType(RenderType renderType) throws IllegalStateException {
-        Validate.notNull(renderType, "RenderType cannot be null");
+        Preconditions.checkArgument(renderType != null, "RenderType cannot be null");
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         this.objective.setRenderType(CraftScoreboardTranslations.fromBukkitRender(renderType));
     }
 
     @Override
     public RenderType getRenderType() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return CraftScoreboardTranslations.toBukkitRender(this.objective.getRenderType());
     }
 
     @Override
     public Score getScore(OfflinePlayer player) throws IllegalArgumentException, IllegalStateException {
-        Validate.notNull(player, "Player cannot be null");
+        Preconditions.checkArgument(player != null, "Player cannot be null");
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return new CraftScore(this, player.getName());
     }
 
     @Override
     public Score getScore(String entry) throws IllegalArgumentException, IllegalStateException {
-        Validate.notNull(entry, "Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
-        Validate.isTrue(entry.length() <= Short.MAX_VALUE, "Score '" + entry + "' is longer than the limit of 32767 characters");
+        Preconditions.checkArgument(entry.length() <= Short.MAX_VALUE, "Score '" + entry + "' is longer than the limit of 32767 characters");
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return new CraftScore(this, entry);
     }
@@ -141,9 +141,7 @@ final class CraftObjective extends CraftScoreboardComponent implements Objective
 
     @Override
     CraftScoreboard checkState() throws IllegalStateException {
-        if (getScoreboard().board.getObjective(objective.getName()) == null) {
+        Preconditions.checkState(getScoreboard().board.getObjective(objective.getName()) != null, "Unregistered scoreboard component");
-            throw new IllegalStateException("Unregistered scoreboard component");
-        }
 
         return getScoreboard();
     }

paper-server/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java

@@ -1,13 +1,12 @@
 package org.bukkit.craftbukkit.scoreboard;
 
 import com.google.common.base.Function;
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
-import java.util.Collection;
 import net.minecraft.world.scores.Scoreboard;
 import net.minecraft.world.scores.ScoreboardObjective;
 import net.minecraft.world.scores.ScoreboardTeam;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.craftbukkit.util.CraftChatMessage;
@@ -47,13 +46,13 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public CraftObjective registerNewObjective(String name, Criteria criteria, String displayName, RenderType renderType) throws IllegalArgumentException {
-        Validate.notNull(name, "Objective name cannot be null");
+        Preconditions.checkArgument(name != null, "Objective name cannot be null");
-        Validate.notNull(criteria, "Criteria cannot be null");
+        Preconditions.checkArgument(criteria != null, "Criteria cannot be null");
-        Validate.notNull(displayName, "Display name cannot be null");
+        Preconditions.checkArgument(displayName != null, "Display name cannot be null");
-        Validate.notNull(renderType, "RenderType cannot be null");
+        Preconditions.checkArgument(renderType != null, "RenderType cannot be null");
-        Validate.isTrue(name.length() <= Short.MAX_VALUE, "The name '" + name + "' is longer than the limit of 32767 characters");
+        Preconditions.checkArgument(name.length() <= Short.MAX_VALUE, "The name '%s' is longer than the limit of 32767 characters (%s)", name, name.length());
-        Validate.isTrue(displayName.length() <= 128, "The display name '" + displayName + "' is longer than the limit of 128 characters");
+        Preconditions.checkArgument(displayName.length() <= 128, "The display name '%s' is longer than the limit of 128 characters (%s)", displayName, displayName.length());
-        Validate.isTrue(board.getObjective(name) == null, "An objective of name '" + name + "' already exists");
+        Preconditions.checkArgument(board.getObjective(name) == null, "An objective of name '%s' already exists", name);
 
         ScoreboardObjective objective = board.addObjective(name, ((CraftCriteria) criteria).criteria, CraftChatMessage.fromStringOrNull(displayName), CraftScoreboardTranslations.fromBukkitRender(renderType));
         return new CraftObjective(this, objective);
@@ -61,17 +60,17 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public Objective getObjective(String name) throws IllegalArgumentException {
-        Validate.notNull(name, "Name cannot be null");
+        Preconditions.checkArgument(name != null, "Objective name cannot be null");
         ScoreboardObjective nms = board.getObjective(name);
         return nms == null ? null : new CraftObjective(this, nms);
     }
 
     @Override
     public ImmutableSet<Objective> getObjectivesByCriteria(String criteria) throws IllegalArgumentException {
-        Validate.notNull(criteria, "Criteria cannot be null");
+        Preconditions.checkArgument(criteria != null, "Criteria name cannot be null");
 
         ImmutableSet.Builder<Objective> objectives = ImmutableSet.builder();
-        for (ScoreboardObjective netObjective : (Collection<ScoreboardObjective>) this.board.getObjectives()) {
+        for (ScoreboardObjective netObjective : this.board.getObjectives()) {
             CraftObjective objective = new CraftObjective(this, netObjective);
             if (objective.getCriteria().equals(criteria)) {
                 objectives.add(objective);
@@ -82,7 +81,7 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public ImmutableSet<Objective> getObjectivesByCriteria(Criteria criteria) throws IllegalArgumentException {
-        Validate.notNull(criteria, "Criteria cannot be null");
+        Preconditions.checkArgument(criteria != null, "Criteria cannot be null");
 
         ImmutableSet.Builder<Objective> objectives = ImmutableSet.builder();
         for (ScoreboardObjective netObjective : board.getObjectives()) {
@@ -97,18 +96,12 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public ImmutableSet<Objective> getObjectives() {
-        return ImmutableSet.copyOf(Iterables.transform((Collection<ScoreboardObjective>) this.board.getObjectives(), new Function<ScoreboardObjective, Objective>() {
+        return ImmutableSet.copyOf(Iterables.transform(this.board.getObjectives(), (Function<ScoreboardObjective, Objective>) input -> new CraftObjective(CraftScoreboard.this, input)));
-
-            @Override
-            public Objective apply(ScoreboardObjective input) {
-                return new CraftObjective(CraftScoreboard.this, input);
-            }
-        }));
     }
 
     @Override
     public Objective getObjective(DisplaySlot slot) throws IllegalArgumentException {
-        Validate.notNull(slot, "Display slot cannot be null");
+        Preconditions.checkArgument(slot != null, "Display slot cannot be null");
         ScoreboardObjective objective = board.getDisplayObjective(CraftScoreboardTranslations.fromBukkitSlot(slot));
         if (objective == null) {
             return null;
@@ -118,17 +111,17 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public ImmutableSet<Score> getScores(OfflinePlayer player) throws IllegalArgumentException {
-        Validate.notNull(player, "OfflinePlayer cannot be null");
+        Preconditions.checkArgument(player != null, "OfflinePlayer cannot be null");
 
         return getScores(player.getName());
     }
 
     @Override
     public ImmutableSet<Score> getScores(String entry) throws IllegalArgumentException {
-        Validate.notNull(entry, "Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
 
         ImmutableSet.Builder<Score> scores = ImmutableSet.builder();
-        for (ScoreboardObjective objective : (Collection<ScoreboardObjective>) this.board.getObjectives()) {
+        for (ScoreboardObjective objective : this.board.getObjectives()) {
             scores.add(new CraftScore(new CraftObjective(this, objective), entry));
         }
         return scores.build();
@@ -136,23 +129,23 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public void resetScores(OfflinePlayer player) throws IllegalArgumentException {
-        Validate.notNull(player, "OfflinePlayer cannot be null");
+        Preconditions.checkArgument(player != null, "OfflinePlayer cannot be null");
 
         resetScores(player.getName());
     }
 
     @Override
     public void resetScores(String entry) throws IllegalArgumentException {
-        Validate.notNull(entry, "Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
 
-        for (ScoreboardObjective objective : (Collection<ScoreboardObjective>) this.board.getObjectives()) {
+        for (ScoreboardObjective objective : this.board.getObjectives()) {
             board.resetPlayerScore(entry, objective);
         }
     }
 
     @Override
     public Team getPlayerTeam(OfflinePlayer player) throws IllegalArgumentException {
-        Validate.notNull(player, "OfflinePlayer cannot be null");
+        Preconditions.checkArgument(player != null, "OfflinePlayer cannot be null");
 
         ScoreboardTeam team = board.getPlayersTeam(player.getName());
         return team == null ? null : new CraftTeam(this, team);
@@ -160,7 +153,7 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public Team getEntryTeam(String entry) throws IllegalArgumentException {
-        Validate.notNull(entry, "Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
 
         ScoreboardTeam team = board.getPlayersTeam(entry);
         return team == null ? null : new CraftTeam(this, team);
@@ -168,7 +161,7 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public Team getTeam(String teamName) throws IllegalArgumentException {
-        Validate.notNull(teamName, "Team name cannot be null");
+        Preconditions.checkArgument(teamName != null, "Team name cannot be null");
 
         ScoreboardTeam team = board.getPlayerTeam(teamName);
         return team == null ? null : new CraftTeam(this, team);
@@ -176,20 +169,14 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public ImmutableSet<Team> getTeams() {
-        return ImmutableSet.copyOf(Iterables.transform((Collection<ScoreboardTeam>) this.board.getPlayerTeams(), new Function<ScoreboardTeam, Team>() {
+        return ImmutableSet.copyOf(Iterables.transform(this.board.getPlayerTeams(), (Function<ScoreboardTeam, Team>) input -> new CraftTeam(CraftScoreboard.this, input)));
-
-            @Override
-            public Team apply(ScoreboardTeam input) {
-                return new CraftTeam(CraftScoreboard.this, input);
-            }
-        }));
     }
 
     @Override
     public Team registerNewTeam(String name) throws IllegalArgumentException {
-        Validate.notNull(name, "Team name cannot be null");
+        Preconditions.checkArgument(name != null, "Team name cannot be null");
-        Validate.isTrue(name.length() <= Short.MAX_VALUE, "Team name '" + name + "' is longer than the limit of 32767 characters");
+        Preconditions.checkArgument(name.length() <= Short.MAX_VALUE, "Team name '%s' is longer than the limit of 32767 characters (%s)", name, name.length());
-        Validate.isTrue(board.getPlayerTeam(name) == null, "Team name '" + name + "' is already in use");
+        Preconditions.checkArgument(board.getPlayerTeam(name) == null, "Team name '%s' is already in use", name);
 
         return new CraftTeam(this, board.addPlayerTeam(name));
     }
@@ -214,7 +201,7 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
 
     @Override
     public void clearSlot(DisplaySlot slot) throws IllegalArgumentException {
-        Validate.notNull(slot, "Slot cannot be null");
+        Preconditions.checkArgument(slot != null, "Slot cannot be null");
         board.setDisplayObjective(CraftScoreboardTranslations.fromBukkitSlot(slot), null);
     }
 

paper-server/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.scoreboard;
 
+import com.google.common.base.Preconditions;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -16,7 +17,6 @@ import net.minecraft.world.scores.ScoreboardObjective;
 import net.minecraft.world.scores.ScoreboardScore;
 import net.minecraft.world.scores.ScoreboardTeam;
 import net.minecraft.world.scores.criteria.IScoreboardCriteria;
-import org.apache.commons.lang.Validate;
 import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.bukkit.craftbukkit.util.WeakCollection;
 import org.bukkit.entity.Player;
@@ -54,7 +54,7 @@ public final class CraftScoreboardManager implements ScoreboardManager {
 
     // CraftBukkit method
     public void setPlayerBoard(CraftPlayer player, org.bukkit.scoreboard.Scoreboard bukkitScoreboard) throws IllegalArgumentException {
-        Validate.isTrue(bukkitScoreboard instanceof CraftScoreboard, "Cannot set player scoreboard to an unregistered Scoreboard");
+        Preconditions.checkArgument(bukkitScoreboard instanceof CraftScoreboard, "Cannot set player scoreboard to an unregistered Scoreboard");
 
         CraftScoreboard scoreboard = (CraftScoreboard) bukkitScoreboard;
         net.minecraft.world.scores.Scoreboard oldboard = getPlayerBoard(player).getHandle();

paper-server/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftTeam.java

@@ -1,19 +1,17 @@
 package org.bukkit.craftbukkit.scoreboard;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import java.util.Set;
 import net.minecraft.world.scores.ScoreboardTeam;
 import net.minecraft.world.scores.ScoreboardTeamBase;
 import net.minecraft.world.scores.ScoreboardTeamBase.EnumNameTagVisibility;
-import org.apache.commons.lang.Validate;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.craftbukkit.util.CraftChatMessage;
 import org.bukkit.scoreboard.NameTagVisibility;
 import org.bukkit.scoreboard.Team;
-import org.bukkit.scoreboard.Team.Option;
-import org.bukkit.scoreboard.Team.OptionStatus;
 
 final class CraftTeam extends CraftScoreboardComponent implements Team {
     private final ScoreboardTeam team;
@@ -25,119 +23,121 @@ final class CraftTeam extends CraftScoreboardComponent implements Team {
 
     @Override
     public String getName() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return team.getName();
     }
 
     @Override
     public String getDisplayName() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return CraftChatMessage.fromComponent(team.getDisplayName());
     }
 
     @Override
     public void setDisplayName(String displayName) throws IllegalStateException {
-        Validate.notNull(displayName, "Display name cannot be null");
+        Preconditions.checkArgument(displayName != null, "Display name cannot be null");
-        Validate.isTrue(ChatColor.stripColor(displayName).length() <= 128, "Display name '" + displayName + "' is longer than the limit of 128 characters");
+        int lengthStripedDisplayName = ChatColor.stripColor(displayName).length();
-        CraftScoreboard scoreboard = checkState();
+        Preconditions.checkArgument(lengthStripedDisplayName <= 128, "Display name '%s' is longer than the limit of 128 characters (%s)", displayName, lengthStripedDisplayName);
+        checkState();
 
         team.setDisplayName(CraftChatMessage.fromString(displayName)[0]); // SPIGOT-4112: not nullable
     }
 
     @Override
     public String getPrefix() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return CraftChatMessage.fromComponent(team.getPlayerPrefix());
     }
 
     @Override
     public void setPrefix(String prefix) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(prefix, "Prefix cannot be null");
+        Preconditions.checkArgument(prefix != null, "Prefix cannot be null");
-        Validate.isTrue(ChatColor.stripColor(prefix).length() <= 64, "Prefix '" + prefix + "' is longer than the limit of 64 characters");
+        int lengthStripedPrefix = ChatColor.stripColor(prefix).length();
-        CraftScoreboard scoreboard = checkState();
+        Preconditions.checkArgument(lengthStripedPrefix <= 64, "Prefix '%s' is longer than the limit of 64 characters (%s)", prefix, lengthStripedPrefix);
+        checkState();
 
         team.setPlayerPrefix(CraftChatMessage.fromStringOrNull(prefix));
     }
 
     @Override
     public String getSuffix() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return CraftChatMessage.fromComponent(team.getPlayerSuffix());
     }
 
     @Override
     public void setSuffix(String suffix) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(suffix, "Suffix cannot be null");
+        Preconditions.checkArgument(suffix != null, "Suffix cannot be null");
-        Validate.isTrue(ChatColor.stripColor(suffix).length() <= 64, "Suffix '" + suffix + "' is longer than the limit of 64 characters");
+        int lengthStripedSuffix = ChatColor.stripColor(suffix).length();
-        CraftScoreboard scoreboard = checkState();
+        Preconditions.checkArgument(lengthStripedSuffix <= 64, "Suffix '%s' is longer than the limit of 64 characters (%s)", suffix, lengthStripedSuffix);
 
         team.setPlayerSuffix(CraftChatMessage.fromStringOrNull(suffix));
     }
 
     @Override
     public ChatColor getColor() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return CraftChatMessage.getColor(team.getColor());
     }
 
     @Override
     public void setColor(ChatColor color) {
-        Validate.notNull(color, "Color cannot be null");
+        Preconditions.checkArgument(color != null, "Color cannot be null");
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         team.setColor(CraftChatMessage.getColor(color));
     }
 
     @Override
     public boolean allowFriendlyFire() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return team.isAllowFriendlyFire();
     }
 
     @Override
     public void setAllowFriendlyFire(boolean enabled) throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         team.setAllowFriendlyFire(enabled);
     }
 
     @Override
     public boolean canSeeFriendlyInvisibles() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return team.canSeeFriendlyInvisibles();
     }
 
     @Override
     public void setCanSeeFriendlyInvisibles(boolean enabled) throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         team.setSeeFriendlyInvisibles(enabled);
     }
 
     @Override
     public NameTagVisibility getNameTagVisibility() throws IllegalArgumentException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return notchToBukkit(team.getNameTagVisibility());
     }
 
     @Override
     public void setNameTagVisibility(NameTagVisibility visibility) throws IllegalArgumentException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         team.setNameTagVisibility(bukkitToNotch(visibility));
     }
 
     @Override
     public Set<OfflinePlayer> getPlayers() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         ImmutableSet.Builder<OfflinePlayer> players = ImmutableSet.builder();
         for (String playerName : team.getPlayers()) {
@@ -148,7 +148,7 @@ final class CraftTeam extends CraftScoreboardComponent implements Team {
 
     @Override
     public Set<String> getEntries() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         ImmutableSet.Builder<String> entries = ImmutableSet.builder();
         for (String playerName : team.getPlayers()) {
@@ -159,20 +159,20 @@ final class CraftTeam extends CraftScoreboardComponent implements Team {
 
     @Override
     public int getSize() throws IllegalStateException {
-        CraftScoreboard scoreboard = checkState();
+        checkState();
 
         return team.getPlayers().size();
     }
 
     @Override
     public void addPlayer(OfflinePlayer player) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(player, "OfflinePlayer cannot be null");
+        Preconditions.checkArgument(player != null, "OfflinePlayer cannot be null");
         addEntry(player.getName());
     }
 
     @Override
     public void addEntry(String entry) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(entry, "Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
         CraftScoreboard scoreboard = checkState();
 
         scoreboard.board.addPlayerToTeam(entry, team);
@@ -180,13 +180,13 @@ final class CraftTeam extends CraftScoreboardComponent implements Team {
 
     @Override
     public boolean removePlayer(OfflinePlayer player) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(player, "OfflinePlayer cannot be null");
+        Preconditions.checkArgument(player != null, "OfflinePlayer cannot be null");
         return removeEntry(player.getName());
     }
 
     @Override
     public boolean removeEntry(String entry) throws IllegalStateException, IllegalArgumentException {
-        Validate.notNull(entry, "Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
         CraftScoreboard scoreboard = checkState();
 
         if (!team.getPlayers().contains(entry)) {
@@ -199,15 +199,14 @@ final class CraftTeam extends CraftScoreboardComponent implements Team {
 
     @Override
     public boolean hasPlayer(OfflinePlayer player) throws IllegalArgumentException, IllegalStateException {
-        Validate.notNull(player, "OfflinePlayer cannot be null");
+        Preconditions.checkArgument(player != null, "OfflinePlayer cannot be null");
         return hasEntry(player.getName());
     }
 
     @Override
     public boolean hasEntry(String entry) throws IllegalArgumentException, IllegalStateException {
-        Validate.notNull("Entry cannot be null");
+        Preconditions.checkArgument(entry != null, "Entry cannot be null");
-
+        checkState();
-        CraftScoreboard scoreboard = checkState();
 
         return team.getPlayers().contains(entry);
     }
@@ -286,9 +285,7 @@ final class CraftTeam extends CraftScoreboardComponent implements Team {
 
     @Override
     CraftScoreboard checkState() throws IllegalStateException {
-        if (getScoreboard().board.getPlayerTeam(team.getName()) == null) {
+        Preconditions.checkState(getScoreboard().board.getPlayerTeam(team.getName()) != null, "Unregistered scoreboard component");
-            throw new IllegalStateException("Unregistered scoreboard component");
-        }
 
         return getScoreboard();
     }

paper-server/src/main/java/org/bukkit/craftbukkit/structure/CraftStructure.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.structure;
 
+import com.google.common.base.Preconditions;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -14,7 +15,6 @@ import net.minecraft.world.level.block.EnumBlockRotation;
 import net.minecraft.world.level.levelgen.structure.templatesystem.DefinedStructure;
 import net.minecraft.world.level.levelgen.structure.templatesystem.DefinedStructureInfo;
 import net.minecraft.world.level.levelgen.structure.templatesystem.DefinedStructureProcessorRotation;
-import org.apache.commons.lang3.Validate;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.RegionAccessor;
@@ -42,9 +42,10 @@ public class CraftStructure implements Structure {
 
     @Override
     public void place(Location location, boolean includeEntities, StructureRotation structureRotation, Mirror mirror, int palette, float integrity, Random random) {
+        Preconditions.checkArgument(location != null, "Location cannot be null");
         location.checkFinite();
         World world = location.getWorld();
-        Validate.notNull(world, "location#getWorld() cannot be null");
+        Preconditions.checkArgument(world != null, "The World of Location cannot be null");
 
         BlockVector blockVector = new BlockVector(location.getBlockX(), location.getBlockY(), location.getBlockZ());
         place(world, blockVector, includeEntities, structureRotation, mirror, palette, integrity, random);
@@ -52,12 +53,11 @@ public class CraftStructure implements Structure {
 
     @Override
     public void place(RegionAccessor regionAccessor, BlockVector location, boolean includeEntities, StructureRotation structureRotation, Mirror mirror, int palette, float integrity, Random random) {
-        Validate.notNull(regionAccessor, "regionAccessor can not be null");
+        Preconditions.checkArgument(location != null, "Location cannot be null");
+        Preconditions.checkArgument(regionAccessor != null, "RegionAccessor cannot be null");
         location.checkFinite();
 
-        if (integrity < 0F || integrity > 1F) {
+        Preconditions.checkArgument(integrity >= 0F && integrity <= 1F, "Integrity value (%S) must be between 0 and 1 inclusive", integrity);
-            throw new IllegalArgumentException("Integrity must be between 0 and 1 inclusive. Was \"" + integrity + "\"");
-        }
 
         RandomSource randomSource = new RandomSourceWrapper(random);
         DefinedStructureInfo definedstructureinfo = new DefinedStructureInfo()
@@ -74,10 +74,10 @@ public class CraftStructure implements Structure {
 
     @Override
     public void fill(Location corner1, Location corner2, boolean includeEntities) {
-        Validate.notNull(corner1, "corner1 cannot be null");
+        Preconditions.checkArgument(corner1 != null, "Location corner1 cannot be null");
-        Validate.notNull(corner2, "corner2 cannot be null");
+        Preconditions.checkArgument(corner2 != null, "Location corner2 cannot be null");
         World world = corner1.getWorld();
-        Validate.notNull(world, "corner1#getWorld() cannot be null");
+        Preconditions.checkArgument(world != null, "World of corner1 Location cannot be null");
 
         Location origin = new Location(world, Math.min(corner1.getBlockX(), corner2.getBlockX()), Math.min(corner1.getBlockY(), corner2.getBlockY()), Math.min(corner1.getBlockZ(), corner2.getBlockZ()));
         BlockVector size = new BlockVector(Math.abs(corner1.getBlockX() - corner2.getBlockX()), Math.abs(corner1.getBlockY() - corner2.getBlockY()), Math.abs(corner1.getBlockZ() - corner2.getBlockZ()));
@@ -86,13 +86,11 @@ public class CraftStructure implements Structure {
 
     @Override
     public void fill(Location origin, BlockVector size, boolean includeEntities) {
-        Validate.notNull(origin, "origin cannot be null");
+        Preconditions.checkArgument(origin != null, "Location origin cannot be null");
         World world = origin.getWorld();
-        Validate.notNull(world, "origin#getWorld() cannot be null");
+        Preconditions.checkArgument(world != null, "World of Location origin cannot be null");
-        Validate.notNull(size, "size cannot be null");
+        Preconditions.checkArgument(size != null, "BlockVector size cannot be null");
-        if (size.getBlockX() < 1 || size.getBlockY() < 1 || size.getBlockZ() < 1) {
+        Preconditions.checkArgument(size.getBlockX() >= 1 && size.getBlockY() >= 1 && size.getBlockZ() >= 1, "Size must be at least 1x1x1 but was %sx%sx%s", size.getBlockX(), size.getBlockY(), size.getBlockZ());
-            throw new IllegalArgumentException("Size must be at least 1x1x1 but was " + size.getBlockX() + "x" + size.getBlockY() + "x" + size.getBlockZ());
-        }
 
         structure.fillFromWorld(((CraftWorld) world).getHandle(), CraftLocation.toBlockPosition(origin), CraftBlockVector.toBlockPosition(size), includeEntities, Blocks.STRUCTURE_VOID);
     }

paper-server/src/main/java/org/bukkit/craftbukkit/structure/CraftStructureManager.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.structure;
 
+import com.google.common.base.Preconditions;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -17,7 +18,6 @@ import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.resources.MinecraftKey;
 import net.minecraft.world.level.levelgen.structure.templatesystem.DefinedStructure;
 import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
-import org.apache.commons.lang3.Validate;
 import org.bukkit.NamespacedKey;
 import org.bukkit.craftbukkit.util.CraftNamespacedKey;
 import org.bukkit.structure.Structure;
@@ -35,16 +35,14 @@ public class CraftStructureManager implements StructureManager {
     public Map<NamespacedKey, Structure> getStructures() {
         Map<NamespacedKey, Structure> cachedStructures = new HashMap<>();
         for (Map.Entry<MinecraftKey, Optional<DefinedStructure>> entry : structureManager.structureRepository.entrySet()) {
-            entry.getValue().ifPresent(definedStructure -> {
+            entry.getValue().ifPresent(definedStructure -> cachedStructures.put(CraftNamespacedKey.fromMinecraft(entry.getKey()), new CraftStructure(definedStructure)));
-                cachedStructures.put(CraftNamespacedKey.fromMinecraft(entry.getKey()), new CraftStructure(definedStructure));
-            });
         }
         return Collections.unmodifiableMap(cachedStructures);
     }
 
     @Override
     public Structure getStructure(NamespacedKey structureKey) {
-        Validate.notNull(structureKey, "structureKey cannot be null");
+        Preconditions.checkArgument(structureKey != null, "NamespacedKey structureKey cannot be null");
 
         final Optional<DefinedStructure> definedStructure = structureManager.structureRepository.get(CraftNamespacedKey.toMinecraft(structureKey));
         if (definedStructure == null) {
@@ -83,7 +81,8 @@ public class CraftStructureManager implements StructureManager {
 
     @Override
     public void saveStructure(NamespacedKey structureKey, Structure structure) throws IOException {
-        Validate.notNull(structure, "structure cannot be null");
+        Preconditions.checkArgument(structureKey != null, "NamespacedKey structure cannot be null");
+        Preconditions.checkArgument(structure != null, "Structure cannot be null");
 
         File structureFile = getStructureFile(structureKey);
         Files.createDirectories(structureFile.toPath().getParent());
@@ -92,7 +91,8 @@ public class CraftStructureManager implements StructureManager {
 
     @Override
     public Structure registerStructure(NamespacedKey structureKey, Structure structure) {
-        Validate.notNull(structure, "structure cannot be null");
+        Preconditions.checkArgument(structureKey != null, "NamespacedKey structureKey cannot be null");
+        Preconditions.checkArgument(structure != null, "Structure cannot be null");
         MinecraftKey minecraftKey = createAndValidateMinecraftStructureKey(structureKey);
 
         final Optional<DefinedStructure> optionalDefinedStructure = Optional.of(((CraftStructure) structure).getHandle());
@@ -102,6 +102,7 @@ public class CraftStructureManager implements StructureManager {
 
     @Override
     public Structure unregisterStructure(NamespacedKey structureKey) {
+        Preconditions.checkArgument(structureKey != null, "NamespacedKey structureKey cannot be null");
         MinecraftKey minecraftKey = createAndValidateMinecraftStructureKey(structureKey);
 
         final Optional<DefinedStructure> previousStructure = structureManager.structureRepository.remove(minecraftKey);
@@ -132,7 +133,7 @@ public class CraftStructureManager implements StructureManager {
 
     @Override
     public Structure loadStructure(File file) throws IOException {
-        Validate.notNull(file, "file cannot be null");
+        Preconditions.checkArgument(file != null, "File cannot be null");
 
         FileInputStream fileinputstream = new FileInputStream(file);
         return loadStructure(fileinputstream);
@@ -140,15 +141,15 @@ public class CraftStructureManager implements StructureManager {
 
     @Override
     public Structure loadStructure(InputStream inputStream) throws IOException {
-        Validate.notNull(inputStream, "inputStream cannot be null");
+        Preconditions.checkArgument(inputStream != null, "inputStream cannot be null");
 
         return new CraftStructure(structureManager.readStructure(inputStream));
     }
 
     @Override
     public void saveStructure(File file, Structure structure) throws IOException {
-        Validate.notNull(file, "file cannot be null");
+        Preconditions.checkArgument(file != null, "file cannot be null");
-        Validate.notNull(structure, "structure cannot be null");
+        Preconditions.checkArgument(structure != null, "structure cannot be null");
 
         FileOutputStream fileoutputstream = new FileOutputStream(file);
         saveStructure(fileoutputstream, structure);
@@ -156,8 +157,8 @@ public class CraftStructureManager implements StructureManager {
 
     @Override
     public void saveStructure(OutputStream outputStream, Structure structure) throws IOException {
-        Validate.notNull(outputStream, "outputStream cannot be null");
+        Preconditions.checkArgument(outputStream != null, "outputStream cannot be null");
-        Validate.notNull(structure, "structure cannot be null");
+        Preconditions.checkArgument(structure != null, "structure cannot be null");
 
         NBTTagCompound nbttagcompound = ((CraftStructure) structure).getHandle().save(new NBTTagCompound());
         NBTCompressedStreamTools.writeCompressed(nbttagcompound, outputStream);
@@ -169,17 +170,16 @@ public class CraftStructureManager implements StructureManager {
     }
 
     private MinecraftKey createAndValidateMinecraftStructureKey(NamespacedKey structureKey) {
-        Validate.notNull(structureKey, "structureKey cannot be null");
+        Preconditions.checkArgument(structureKey != null, "NamespacedKey structureKey cannot be null");
 
         MinecraftKey minecraftkey = CraftNamespacedKey.toMinecraft(structureKey);
-        if (minecraftkey.getPath().contains("//")) {
+        Preconditions.checkArgument(!minecraftkey.getPath().contains("//"), "Resource key for Structures can not contain \"//\"");
-            throw new IllegalArgumentException("Resource key for Structures can not contain \"//\"");
-        }
         return minecraftkey;
     }
 
     @Override
     public Structure copy(Structure structure) {
+        Preconditions.checkArgument(structure != null, "Structure cannot be null");
         return new CraftStructure(structureManager.readStructure(((CraftStructure) structure).getHandle().save(new NBTTagCompound())));
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java

@@ -268,9 +268,7 @@ public final class CraftMagicNumbers implements UnsafeValues {
 
     @Override
     public Advancement loadAdvancement(NamespacedKey key, String advancement) {
-        if (Bukkit.getAdvancement(key) != null) {
+        Preconditions.checkArgument(Bukkit.getAdvancement(key) == null, "Advancement %s already exists", key);
-            throw new IllegalArgumentException("Advancement " + key + " already exists.");
-        }
         MinecraftKey minecraftkey = CraftNamespacedKey.toMinecraft(key);
 
         JsonElement jsonelement = AdvancementDataWorld.GSON.fromJson(advancement, JsonElement.class);

paper-server/src/main/java/org/bukkit/craftbukkit/util/LazyPlayerSet.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.util;
 
+import com.google.common.base.Preconditions;
 import java.util.HashSet;
 import java.util.List;
 import net.minecraft.server.MinecraftServer;
@@ -16,9 +17,7 @@ public class LazyPlayerSet extends LazyHashSet<Player> {
 
     @Override
     HashSet<Player> makeReference() {
-        if (reference != null) {
+        Preconditions.checkState(reference == null, "Reference already created!");
-            throw new IllegalStateException("Reference already created!");
-        }
         List<EntityPlayer> players = server.getPlayerList().players;
         HashSet<Player> reference = new HashSet<Player>(players.size());
         for (EntityPlayer player : players) {

paper-server/src/main/java/org/bukkit/craftbukkit/util/UnsafeList.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.util;
 
+import com.google.common.base.Preconditions;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
@@ -273,9 +274,7 @@ public class UnsafeList<E> extends AbstractList<E> implements List<E>, RandomAcc
 
         @Override
         public void remove() {
-            if (lastRet < 0) {
+            Preconditions.checkState(lastRet >= 0, "");
-                throw new IllegalStateException();
-            }
 
             if (modCount != expectedModCount) {
                 throw new ConcurrentModificationException();

paper-server/src/main/java/org/bukkit/craftbukkit/util/Waitable.java

@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.util;
 
+import com.google.common.base.Preconditions;
 import java.util.concurrent.ExecutionException;
 
 public abstract class Waitable<T> implements Runnable {
@@ -15,9 +16,7 @@ public abstract class Waitable<T> implements Runnable {
     @Override
     public final void run() {
         synchronized (this) {
-            if (status != Status.WAITING) {
+            Preconditions.checkState(status == Status.WAITING, "Invalid state %s", status);
-                throw new IllegalStateException("Invalid state " + status);
-            }
             status = Status.RUNNING;
         }
         try {

paper-server/src/main/java/org/bukkit/craftbukkit/util/WeakCollection.java

@@ -1,23 +1,23 @@
 package org.bukkit.craftbukkit.util;
 
+import com.google.common.base.Preconditions;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
-import org.apache.commons.lang.Validate;
 
 public final class WeakCollection<T> implements Collection<T> {
     static final Object NO_VALUE = new Object();
     private final Collection<WeakReference<T>> collection;
 
     public WeakCollection() {
-        collection = new ArrayList<WeakReference<T>>();
+        collection = new ArrayList<>();
     }
 
     @Override
     public boolean add(T value) {
-        Validate.notNull(value, "Cannot add null value");
+        Preconditions.checkArgument(value != null, "Cannot add null value");
         return collection.add(new WeakReference<T>(value));
     }
 
@@ -26,7 +26,7 @@ public final class WeakCollection<T> implements Collection<T> {
         Collection<WeakReference<T>> values = this.collection;
         boolean ret = false;
         for (T value : collection) {
-            Validate.notNull(value, "Cannot add null value");
+            Preconditions.checkArgument(value != null, "Cannot add null value");
             ret |= values.add(new WeakReference<T>(value));
         }
         return ret;
@@ -103,9 +103,7 @@ public final class WeakCollection<T> implements Collection<T> {
 
             @Override
             public void remove() throws IllegalStateException {
-                if (value != NO_VALUE) {
+                Preconditions.checkState(value == NO_VALUE, "No last element");
-                    throw new IllegalStateException("No last element");
-                }
 
                 value = null;
                 it.remove();