Fix several NPE cases, apply final to relevant fields, remove unused code

The suggested changes were found with FindBugs, some of these bugs may be rare cases.

bukkit/src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -79,7 +79,8 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform {
 
         // Check if it's a spigot build with a protocol mod
         try {
-            compatSpigotBuild = NMSUtil.nms("PacketEncoder").getDeclaredField("version") != null;
+            NMSUtil.nms("PacketEncoder").getDeclaredField("version");
+            compatSpigotBuild = true;
         } catch (Exception e) {
             compatSpigotBuild = false;
         }

common/src/main/java/us/myles/ViaVersion/api/protocol/Protocol.java

@@ -191,7 +191,7 @@ public abstract class Protocol {
 
     @AllArgsConstructor
     @Getter
-    class ProtocolPacket {
+    public static class ProtocolPacket {
         State state;
         int oldID;
         int newID;

common/src/main/java/us/myles/ViaVersion/api/type/types/ShortType.java

@@ -27,6 +27,6 @@ public class ShortType extends Type<Short> implements TypeConverter<Short> {
         if (o instanceof Boolean) {
             return ((Boolean) o) ? (short) 1 : 0;
         }
-        return (short) o;
+        return (Short) o;
     }
 }

common/src/main/java/us/myles/ViaVersion/api/type/types/UnsignedByteType.java

@@ -27,6 +27,6 @@ public class UnsignedByteType extends Type<Short> implements TypeConverter<Short
         if (o instanceof Boolean) {
             return ((Boolean) o) ? (short) 1 : 0;
         }
-        return (short) o;
+        return (Short) o;
     }
 }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_11to1_10/Protocol1_11To1_10.java

@@ -87,13 +87,14 @@ public class Protocol1_11To1_10 extends Protocol {
                         int type = wrapper.get(Type.VAR_INT, 1);
 
                         Entity1_11Types.EntityType entType = MetadataRewriter1_11To1_10.rewriteEntityType(type, wrapper.get(Types1_9.METADATA_LIST, 0));
-                        if (entType != null)
+                        if (entType != null) {
                             wrapper.set(Type.VAR_INT, 1, entType.getId());
 
                             // Register Type ID
                             wrapper.user().get(EntityTracker1_11.class).addEntity(entityId, entType);
                             get(MetadataRewriter1_11To1_10.class).handleMetadata(entityId, entType, wrapper.get(Types1_9.METADATA_LIST, 0), wrapper.user());
                         }
+                    }
                 });
             }
         });

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13_1to1_13/packets/EntityPackets.java

@@ -45,10 +45,10 @@ public class EntityPackets {
                                 int data = wrapper.get(Type.INT, 0);
                                 wrapper.set(Type.INT, 0, Protocol1_13_1To1_13.getNewBlockStateId(data));
                             }
-                        }
                             // Register Type ID
                             wrapper.user().get(EntityTracker1_13.class).addEntity(entityId, entType);
                         }
+                    }
                 });
             }
         });

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13_1to1_13/packets/WorldPackets.java

@@ -104,9 +104,9 @@ public class WorldPackets {
                         int id = wrapper.get(Type.INT, 0);
                         int data = wrapper.get(Type.INT, 1);
                         if (id == 1010) { // Play record
-                            wrapper.set(Type.INT, 1, data = InventoryPackets.getNewItemId(data));
+                            wrapper.set(Type.INT, 1, InventoryPackets.getNewItemId(data));
                         } else if (id == 2001) { // Block break + block break sound
-                            wrapper.set(Type.INT, 1, data = Protocol1_13_1To1_13.getNewBlockStateId(data));
+                            wrapper.set(Type.INT, 1, Protocol1_13_1To1_13.getNewBlockStateId(data));
                         }
                     }
                 });

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/ChatRewriter.java

@@ -135,7 +135,9 @@ public class ChatRewriter {
             String oldTranslate = ((TranslatableComponent) component).getTranslate();
             String newTranslate;
             newTranslate = MappingData.translateMapping.get(oldTranslate);
-            if (newTranslate == null) MappingData.mojangTranslation.get(oldTranslate);
+            if (newTranslate == null) {
+                newTranslate = MappingData.mojangTranslation.get(oldTranslate);
+            }
             if (newTranslate != null) {
                 ((TranslatableComponent) component).setTranslate(newTranslate);
             }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/Protocol1_13To1_12_2.java

@@ -40,7 +40,6 @@ import us.myles.ViaVersion.util.GsonUtil;
 import java.util.EnumMap;
 import java.util.Map;
 
-// Development of 1.13 support!
 public class Protocol1_13To1_12_2 extends Protocol {
     public static final Particle1_13Type PARTICLE_TYPE = new Particle1_13Type();
 
@@ -106,8 +105,7 @@ public class Protocol1_13To1_12_2 extends Protocol {
             };
 
     // These are arbitrary rewrite values, it just needs an invalid color code character.
-    protected static EnumMap<ChatColor, Character> SCOREBOARD_TEAM_NAME_REWRITE = new EnumMap<>(ChatColor.class);
+    protected final static EnumMap<ChatColor, Character> SCOREBOARD_TEAM_NAME_REWRITE = new EnumMap<>(ChatColor.class);
-    // @formatter:on
 
     static {
         SCOREBOARD_TEAM_NAME_REWRITE.put(ChatColor.BLACK, 'g');
@@ -363,11 +361,11 @@ public class Protocol1_13To1_12_2 extends Protocol {
                         int id = wrapper.get(Type.INT, 0);
                         int data = wrapper.get(Type.INT, 1);
                         if (id == 1010) { // Play record
-                            wrapper.set(Type.INT, 1, data = MappingData.oldToNewItems.get(data << 4));
+                            wrapper.set(Type.INT, 1, MappingData.oldToNewItems.get(data << 4));
                         } else if (id == 2001) { // Block break + block break sound
                             int blockId = data & 0xFFF;
                             int blockData = data >> 12;
-                            wrapper.set(Type.INT, 1, data = WorldPackets.toNewId(blockId << 4 | blockData));
+                            wrapper.set(Type.INT, 1, WorldPackets.toNewId(blockId << 4 | blockData));
                         }
                     }
                 });

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/blockconnections/RedstoneConnectionHandler.java

@@ -35,7 +35,7 @@ public class RedstoneConnectionHandler extends ConnectionHandler {
         b |= getState(data.getValue("north")) << 2;
         b |= getState(data.getValue("south")) << 4;
         b |= getState(data.getValue("west")) << 6;
-        b |= Integer.valueOf(data.getValue("power")) << 8;
+        b |= Integer.parseInt(data.getValue("power")) << 8;
         return b;
     }
 

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/data/MappingData.java

@@ -21,13 +21,13 @@ import java.util.HashMap;
 import java.util.Map;
 
 public class MappingData {
-    public static BiMap<Integer, Integer> oldToNewItems = HashBiMap.create();
+    public static final BiMap<Integer, Integer> oldToNewItems = HashBiMap.create();
-    public static Map<String, Integer[]> blockTags = new HashMap<>();
+    public static final Map<String, Integer[]> blockTags = new HashMap<>();
-    public static Map<String, Integer[]> itemTags = new HashMap<>();
+    public static final Map<String, Integer[]> itemTags = new HashMap<>();
-    public static Map<String, Integer[]> fluidTags = new HashMap<>();
+    public static final Map<String, Integer[]> fluidTags = new HashMap<>();
-    public static BiMap<Short, String> oldEnchantmentsIds = HashBiMap.create();
+    public static final BiMap<Short, String> oldEnchantmentsIds = HashBiMap.create();
-    public static Map<String, String> translateMapping = new HashMap<>();
+    public static final Map<String, String> translateMapping = new HashMap<>();
-    public static Map<String, String> mojangTranslation = new HashMap<>();
+    public static final Map<String, String> mojangTranslation = new HashMap<>();
     public static Mappings enchantmentMappings;
     public static Mappings soundMappings;
     public static Mappings blockMappings;
@@ -50,7 +50,6 @@ public class MappingData {
         Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 sound mapping...");
         soundMappings = new SoundMappingShortArray(mapping1_12.getAsJsonArray("sounds"), mapping1_13.getAsJsonArray("sounds"));
         Via.getPlatform().getLogger().info("Loading translation mappping");
-        translateMapping = new HashMap<>();
         Map<String, String> translateData = GsonUtil.getGson().fromJson(
                 new InputStreamReader(
                         MappingData.class.getClassLoader()

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/EntityPackets.java

@@ -10,8 +10,8 @@ import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.api.type.types.version.Types1_12;
 import us.myles.ViaVersion.api.type.types.version.Types1_13;
 import us.myles.ViaVersion.packets.State;
-import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.metadata.MetadataRewriter1_13To1_12_2;
 import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.data.EntityTypeRewriter;
+import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.metadata.MetadataRewriter1_13To1_12_2;
 import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.storage.EntityTracker1_13;
 
 public class EntityPackets {
@@ -68,12 +68,12 @@ public class EntityPackets {
                                 }
 
                                 wrapper.set(Type.INT, 0, data);
-                            }
 
-                        }
                                 // Register Type ID
                                 wrapper.user().get(EntityTracker1_13.class).addEntity(entityId, entType);
                             }
+                        }
+                    }
                 });
             }
         });

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/InventoryPackets.java

@@ -624,6 +624,7 @@ public class InventoryPackets {
                         if (oldId == null && newId.startsWith("viaversion:legacy/")) {
                             oldId = Short.valueOf(newId.substring(18));
                         }
+                        if (oldId != null) {
                             enchEntry.put(
                                     new ShortTag(
                                             "id",
@@ -634,6 +635,7 @@ public class InventoryPackets {
                             ench.add(enchEntry);
                         }
                     }
+                }
                 tag.remove("Enchantments");
                 tag.put(ench);
             }
@@ -648,6 +650,7 @@ public class InventoryPackets {
                         if (oldId == null && newId.startsWith("viaversion:legacy/")) {
                             oldId = Short.valueOf(newId.substring(18));
                         }
+                        if (oldId != null) {
                             enchEntry.put(
                                     new ShortTag(
                                             "id",
@@ -658,6 +661,7 @@ public class InventoryPackets {
                             newStoredEnch.add(enchEntry);
                         }
                     }
+                }
                 tag.remove("StoredEnchantments");
                 tag.put(newStoredEnch);
             }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/providers/blockentities/BannerHandler.java

@@ -9,11 +9,11 @@ import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.providers.BlockEntityP
 import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.storage.BlockStorage;
 
 public class BannerHandler implements BlockEntityProvider.BlockEntityHandler {
-    private final int WALL_BANNER_START = 7110; // 4 each
+    private static final int WALL_BANNER_START = 7110; // 4 each
-    private final int WALL_BANNER_STOP = 7173;
+    private static final int WALL_BANNER_STOP = 7173;
 
-    private final int BANNER_START = 6854; // 16 each
+    private static final int BANNER_START = 6854; // 16 each
-    private final int BANNER_STOP = 7109;
+    private static final int BANNER_STOP = 7109;
 
     @Override
     public int transform(UserConnection user, CompoundTag tag) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/providers/blockentities/SkullHandler.java

@@ -9,8 +9,8 @@ import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.providers.BlockEntityP
 import us.myles.ViaVersion.protocols.protocol1_13to1_12_2.storage.BlockStorage;
 
 public class SkullHandler implements BlockEntityProvider.BlockEntityHandler {
-    private final int SKULL_WALL_START = 5447;
+    private static final int SKULL_WALL_START = 5447;
-    private final int SKULL_END = 5566;
+    private static final int SKULL_END = 5566;
 
     @Override
     public int transform(UserConnection user, CompoundTag tag) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/storage/BlockStorage.java

@@ -72,7 +72,7 @@ public class BlockStorage extends StoredObject {
 
     @Data
     @AllArgsConstructor
-    public class ReplacementData {
+    public static class ReplacementData {
         private int original;
         private int replacement;
     }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_14to1_13_2/data/MappingData.java

@@ -12,7 +12,7 @@ import us.myles.ViaVersion.api.data.Mappings;
 import java.util.*;
 
 public class MappingData {
-    public static BiMap<Integer, Integer> oldToNewItems = HashBiMap.create();
+    public final static BiMap<Integer, Integer> oldToNewItems = HashBiMap.create();
     public static Mappings blockStateMappings;
     public static Mappings blockMappings;
     public static Mappings soundMappings;

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_14to1_13_2/packets/EntityPackets.java

@@ -49,7 +49,6 @@ public class EntityPackets {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
                         int entityId = wrapper.get(Type.VAR_INT, 0);
-                        UUID uuid = wrapper.get(Type.UUID, 0);
                         int typeId = wrapper.get(Type.VAR_INT, 1);
 
                         Entity1_13Types.EntityType type1_13 = Entity1_13Types.getTypeFromId(typeId, true);
@@ -95,11 +94,12 @@ public class EntityPackets {
                                 velocity.write(Type.SHORT, wrapper.get(Type.SHORT, 2));
                                 velocity.send(Protocol1_14To1_13_2.class);
                             }
+
+                            // Register Type ID
+                            wrapper.user().get(EntityTracker1_14.class).addEntity(entityId, type1_14);
                         }
 
                         wrapper.set(Type.VAR_INT, 1, typeId);
-                        // Register Type ID
-                        wrapper.user().get(EntityTracker1_14.class).addEntity(entityId, type1_14);
                     }
                 });
             }
@@ -128,14 +128,11 @@ public class EntityPackets {
                     public void handle(PacketWrapper wrapper) throws Exception {
                         int entityId = wrapper.get(Type.VAR_INT, 0);
                         int type = wrapper.get(Type.VAR_INT, 1);
-                        UUID uuid = wrapper.get(Type.UUID, 0);
 
                         type = EntityTypeRewriter.getNewId(type).or(type);
-
-                        Entity1_14Types.EntityType entType = Entity1_14Types.getTypeFromId(type);
-
                         wrapper.set(Type.VAR_INT, 1, type);
 
+                        Entity1_14Types.EntityType entType = Entity1_14Types.getTypeFromId(type);
                         // Register Type ID
                         wrapper.user().get(EntityTracker1_14.class).addEntity(entityId, entType);
 
@@ -173,7 +170,6 @@ public class EntityPackets {
                 handler(new PacketHandler() {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
-                        UUID uuid = wrapper.get(Type.UUID, 0);
                         int entityId = wrapper.get(Type.VAR_INT, 0);
 
                         Entity1_14Types.EntityType entType = Entity1_14Types.EntityType.PLAYER;

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_14to1_13_2/packets/WorldPackets.java

@@ -228,9 +228,9 @@ public class WorldPackets {
                         int id = wrapper.get(Type.INT, 0);
                         int data = wrapper.get(Type.INT, 1);
                         if (id == 1010) { // Play record
-                            wrapper.set(Type.INT, 1, data = InventoryPackets.getNewItemId(data));
+                            wrapper.set(Type.INT, 1, InventoryPackets.getNewItemId(data));
                         } else if (id == 2001) { // Block break + block break sound
-                            wrapper.set(Type.INT, 1, data = Protocol1_14To1_13_2.getNewBlockStateId(data));
+                            wrapper.set(Type.INT, 1, Protocol1_14To1_13_2.getNewBlockStateId(data));
                         }
                     }
                 });

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/types/Chunk1_9_1_2Type.java

@@ -34,7 +34,8 @@ public class Chunk1_9_1_2Type extends PartialType<Chunk, ClientWorld> {
 
         boolean groundUp = input.readBoolean();
         int primaryBitmask = Type.VAR_INT.read(input);
-        int size = Type.VAR_INT.read(input);
+        // Size (unused)
+        Type.VAR_INT.read(input);
 
         BitSet usedSections = new BitSet(16);
         ChunkSection[] sections = new ChunkSection[16];

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/WorldPackets.java

@@ -329,7 +329,7 @@ public class WorldPackets {
             @Override
             public void registerMap() {
                 map(Type.POSITION); // 0 - Position
-                map(Type.VAR_INT, Type.BYTE); // 1 - Block Face
+                map(Type.VAR_INT, Type.UNSIGNED_BYTE); // 1 - Block Face
                 map(Type.VAR_INT, Type.NOTHING); // 2 - Hand
                 create(new ValueCreator() {
                     @Override
@@ -359,7 +359,7 @@ public class WorldPackets {
                 handler(new PacketHandler() {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
-                        int face = wrapper.get(Type.BYTE, 0);
+                        int face = wrapper.get(Type.UNSIGNED_BYTE, 0);
                         if (face == 255)
                             return;
                         Position p = wrapper.get(Type.POSITION, 0);

common/src/main/java/us/myles/ViaVersion/update/UpdateUtil.java

@@ -100,14 +100,14 @@ public class UpdateUtil {
             connection.setDoOutput(true);
             BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
             String input;
-            String content = "";
+            StringBuilder builder = new StringBuilder();
             while ((input = br.readLine()) != null) {
-                content = content + input;
+                builder.append(input);
             }
             br.close();
             JsonObject statistics;
             try {
-                statistics = GsonUtil.getGson().fromJson(content, JsonObject.class);
+                statistics = GsonUtil.getGson().fromJson(builder.toString(), JsonObject.class);
             } catch (JsonParseException e) {
                 e.printStackTrace();
                 return null;

common/src/main/java/us/myles/ViaVersion/util/Config.java

@@ -76,10 +76,10 @@ public abstract class Config implements ConfigurationProvider {
                 defaults.remove(option);
             }
             // Merge with defaultLoader
-            for (Object key : config.keySet()) {
+            for (Map.Entry<String, Object> entry : config.entrySet()) {
                 // Set option in new conf if exists
-                if (defaults.containsKey(key) && !unsupported.contains(key.toString())) {
+                if (defaults.containsKey(entry.getKey()) && !unsupported.contains(entry.getKey())) {
-                    defaults.put((String) key, config.get(key));
+                    defaults.put(entry.getKey(), entry.getValue());
                 }
             }
         } catch (IOException e) {

sponge/src/main/java/us/myles/ViaVersion/sponge/listeners/protocol1_9to1_8/HandItemCache.java

@@ -70,6 +70,7 @@ public class HandItemCache implements Runnable {
             }
         }
         int id = 0;
+        if (GET_ID != null) {
             try {
                 id = (int) GET_ID.invoke(null, itemInHand.getItem());
             } catch (IllegalAccessException e) {
@@ -77,12 +78,15 @@ public class HandItemCache implements Runnable {
             } catch (InvocationTargetException e) {
                 e.printStackTrace();
             }
+        }
         int damage = 0;
+        if (GET_DAMAGE != null) {
             try {
                 damage = (int) GET_DAMAGE.get(itemInHand);
             } catch (IllegalAccessException e) {
                 e.printStackTrace();
             }
+        }
         return new Item((short) id, (byte) itemInHand.getQuantity(), (short) damage, null);
     }
 }