Merge pull request #1036 from KennyTV/master

Remove some more unncessary/doubled map check

bungee/src/main/java/us/myles/ViaVersion/bungee/service/ProtocolDetectorService.java

@@ -27,16 +27,19 @@ public class ProtocolDetectorService implements Runnable {
     public static Integer getProtocolId(String serverName) {
         // Step 1. Check Config
         Map<String, Integer> servers = ((BungeeConfigAPI) Via.getConfig()).getBungeeServerProtocols();
-        if (servers.containsKey(serverName)) {
+        Integer protocol = servers.get(serverName);
-            return servers.get(serverName);
+        if (protocol != null) {
+            return protocol;
         }
         // Step 2. Check Detected
-        if (detectedProtocolIds.containsKey(serverName)) {
+        Integer detectedProtocol = detectedProtocolIds.get(serverName);
-            return detectedProtocolIds.get(serverName);
+        if (detectedProtocol != null) {
+            return detectedProtocol;
         }
         // Step 3. Use Default
-        if (servers.containsKey("default")) {
+        Integer defaultProtocol = servers.get("default");
-            return servers.get("default");
+        if (defaultProtocol != null) {
+            return defaultProtocol;
         }
         // Step 4: Use bungee lowest supported... *cries*
         return BungeeVersionProvider.getLowestSupportedVersion();
@@ -58,10 +61,9 @@ public class ProtocolDetectorService implements Runnable {
                     detectedProtocolIds.put(key, serverPing.getVersion().getProtocol());
                     if (((BungeeConfigAPI) Via.getConfig()).isBungeePingSave()) {
                         Map<String, Integer> servers = ((BungeeConfigAPI) Via.getConfig()).getBungeeServerProtocols();
-                        if (servers.containsKey(key)) {
+                        Integer protocol = servers.get(key);
-                            if (servers.get(key) == serverPing.getVersion().getProtocol()) {
+                        if (protocol != null && protocol == serverPing.getVersion().getProtocol()) {
-                                return;
+                            return;
-                            }
                         }
                         // Ensure we're the only ones writing to the config
                         synchronized (Via.getPlatform().getConfigurationProvider()) {

common/src/main/java/us/myles/ViaVersion/api/platform/providers/ViaProviders.java

@@ -18,15 +18,14 @@ public class ViaProviders {
     }
 
     public <T extends Provider> void use(Class<T> provider, T value) {
-        if (lonelyProviders.contains(provider)) {
+        lonelyProviders.remove(provider);
-            lonelyProviders.remove(provider);
-        }
         providers.put(provider, value);
     }
 
     public <T extends Provider> T get(Class<T> provider) {
-        if (providers.containsKey(provider)) {
+        Provider rawProvider = providers.get(provider);
-            return (T) providers.get(provider);
+        if (rawProvider != null) {
+            return (T) rawProvider;
         } else {
             if (lonelyProviders.contains(provider)) {
                 throw new IllegalStateException("There was no provider for " + provider + ", one is required!");

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

@@ -137,10 +137,8 @@ public abstract class Protocol {
     public void transform(Direction direction, State state, PacketWrapper packetWrapper) throws Exception {
         Pair<State, Integer> statePacket = new Pair<>(state, packetWrapper.getId());
         Map<Pair<State, Integer>, ProtocolPacket> packetMap = (direction == Direction.OUTGOING ? outgoing : incoming);
-        ProtocolPacket protocolPacket;
+        ProtocolPacket protocolPacket = packetMap.get(statePacket);
-        if (packetMap.containsKey(statePacket)) {
+        if (protocolPacket == null) {
-            protocolPacket = packetMap.get(statePacket);
-        } else {
             return;
         }
         // write packet id

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

@@ -165,13 +165,14 @@ public class ProtocolRegistry {
         if (current.size() > 50) return null; // Fail safe, protocol too complicated.
 
         // First check if there is any protocols for this
-        if (!registryMap.containsKey(clientVersion)) {
+        Map<Integer, Protocol> inputMap = registryMap.get(clientVersion);
+        if (inputMap == null) {
             return null; // Not supported
         }
         // Next check there isn't an obvious path
-        Map<Integer, Protocol> inputMap = registryMap.get(clientVersion);
+        Protocol protocol = inputMap.get(serverVersion);
-        if (inputMap.containsKey(serverVersion)) {
+        if (protocol != null) {
-            current.add(new Pair<>(serverVersion, inputMap.get(serverVersion)));
+            current.add(new Pair<>(serverVersion, protocol));
             return current; // Easy solution
         }
         // There might be a more advanced solution... So we'll see if any of the others can get us there
@@ -211,8 +212,9 @@ public class ProtocolRegistry {
     public static List<Pair<Integer, Protocol>> getProtocolPath(int clientVersion, int serverVersion) {
         Pair<Integer, Integer> protocolKey = new Pair<>(clientVersion, serverVersion);
         // Check cache
-        if (pathCache.containsKey(protocolKey)) {
+        List<Pair<Integer, Protocol>> protocolList = pathCache.get(protocolKey);
-            return pathCache.get(protocolKey);
+        if (protocolList != null) {
+            return protocolList;
         }
         // Generate path
         List<Pair<Integer, Protocol>> outputPath = getProtocolPath(new ArrayList<Pair<Integer, Protocol>>(), clientVersion, serverVersion);

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

@@ -77,8 +77,9 @@ public class ProtocolVersion {
     }
 
     public static ProtocolVersion getProtocol(int id) {
-        if (versions.containsKey(id)) {
+        ProtocolVersion protocolVersion = versions.get(id);
-            return versions.get(id);
+        if (protocolVersion != null) {
+            return protocolVersion;
         } else {
             return new ProtocolVersion(id, "Unknown (" + id + ")");
         }

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

@@ -42,8 +42,10 @@ public class BlockEntityRewriter {
     }
 
     public static String toNewIdentifier(String oldId) {
-        if (oldToNewNames.containsKey(oldId))
+        String newName = oldToNewNames.get(oldId);
-            return oldToNewNames.get(oldId);
+        if (newName != null) {
+            return newName;
+        }
         return oldId;
     }
 }

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

@@ -90,8 +90,9 @@ public class EntityIdRewriter {
     public static void toClient(CompoundTag tag) {
         if (tag.get("id") instanceof StringTag) {
             StringTag id = tag.get("id");
-            if (oldToNewNames.containsKey(id.getValue())) {
+            String newName = oldToNewNames.get(id.getValue());
-                id.setValue(oldToNewNames.get(id.getValue()));
+            if (newName != null) {
+                id.setValue(newName);
             }
         }
     }
@@ -117,8 +118,9 @@ public class EntityIdRewriter {
             CompoundTag entityTag = item.getTag().get("EntityTag");
             if (entityTag.get("id") instanceof StringTag) {
                 StringTag id = entityTag.get("id");
-                if (oldToNewNames.inverse().containsKey(id.getValue())) {
+                String newName = oldToNewNames.inverse().get(id.getValue());
-                    id.setValue(oldToNewNames.inverse().get(id.getValue()));
+                if (newName != null) {
+                    id.setValue(newName);
                 }
             }
         }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_11to1_10/storage/EntityTracker.java

@@ -33,9 +33,7 @@ public class EntityTracker extends StoredObject {
     }
 
     public Optional<Entity1_11Types.EntityType> get(int id) {
-        if (!has(id))
+        return Optional.fromNullable(clientEntityTypes.get(id));
-            return Optional.absent();
-        return Optional.of(clientEntityTypes.get(id));
     }
 
     public void addHologram(int entId) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_12to1_11_1/storage/EntityTracker.java

@@ -28,9 +28,7 @@ public class EntityTracker extends StoredObject {
     }
 
     public Optional<Entity1_12Types.EntityType> get(int id) {
-        if (!has(id))
+        return Optional.fromNullable(clientEntityTypes.get(id));
-            return Optional.absent();
-        return Optional.of(clientEntityTypes.get(id));
     }
 
 }

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

@@ -46,11 +46,14 @@ public class EntityNameRewriter {
     }
 
     public static String rewrite(String entName) {
-        if (entityNames.containsKey(entName))
+        String entityName = entityNames.get(entName);
-            return entityNames.get(entName);
+        if (entityName != null) {
-        if (entityNames.containsKey("minecraft:" + entName))
+            return entityName;
-            return entityNames.get("minecraft:" + entName);
+        }
-        else
+        entityName = entityNames.get("minecraft:" + entName);
+        if (entityName != null) {
+            return entityName;
+        } else
             return entName;
     }
 }

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

@@ -39,15 +39,15 @@ public class BlockEntityProvider implements Provider {
             return -1;
 
         String id = (String) tag.get("id").getValue();
-
+        BlockEntityHandler handler = handlers.get(id);
-        if (!handlers.containsKey(id)) {
+        if (handler == null) {
             if (Via.getManager().isDebug()) {
                 Via.getPlatform().getLogger().warning("Unhandled BlockEntity " + id + " full tag: " + tag);
             }
             return -1;
         }
 
-        int newBlock = handlers.get(id).transform(user, tag);
+        int newBlock = handler.transform(user, tag);
 
         if (sendUpdate && newBlock != -1)
             sendBlockChange(user, position, newBlock);

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

@@ -46,10 +46,6 @@ public class PaintingProvider implements Provider {
         // Handle older versions
         if (!motive.startsWith("minecraft:"))
             motive = "minecraft:" + motive.toLowerCase();
-
+        return Optional.fromNullable(paintings.get(motive));
-        if (paintings.containsKey(motive))
-            return Optional.of(paintings.get(motive));
-
-        return Optional.absent();
     }
 }

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

@@ -28,9 +28,7 @@ public class EntityTracker extends StoredObject {
     }
 
     public Optional<Entity1_13Types.EntityType> get(int id) {
-        if (!has(id))
+        return Optional.fromNullable(clientEntityTypes.get(id));
-            return Optional.absent();
-        return Optional.of(clientEntityTypes.get(id));
     }
 
 }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9_3to1_9_1_2/chunks/FakeTileEntity.java

@@ -57,8 +57,9 @@ public class FakeTileEntity {
     }
 
     public static CompoundTag getFromBlock(int x, int y, int z, int block) {
-        if (tileEntities.containsKey(block)) {
+        CompoundTag originalTag = tileEntities.get(block);
-            CompoundTag tag = tileEntities.get(block).clone();
+        if (originalTag != null) {
+            CompoundTag tag = originalTag.clone();
             tag.put(new IntTag("x", x));
             tag.put(new IntTag("y", y));
             tag.put(new IntTag("z", z));

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/ItemRewriter.java

@@ -230,8 +230,9 @@ public class ItemRewriter {
                     tag = new CompoundTag("tag");
                 }
                 CompoundTag entityTag = new CompoundTag("EntityTag");
-                if (ENTTIY_ID_TO_NAME.containsKey((int) item.getData())) {
+                String entityName = ENTTIY_ID_TO_NAME.get((int) item.getData());
-                    StringTag id = new StringTag("id", ENTTIY_ID_TO_NAME.get((int) item.getData()));
+                if (entityName != null) {
+                    StringTag id = new StringTag("id", entityName);
                     entityTag.put(id);
                     tag.put(entityTag);
                 }
@@ -379,12 +380,14 @@ public class ItemRewriter {
         if (oldID >= 16384) {
             oldID -= 8192;
         }
-        if (POTION_INDEX.containsKey(oldID)) {
+
-            return POTION_INDEX.get(oldID);
+        Integer index = POTION_INDEX.get(oldID);
+        if (index != null) {
+            return index;
         }
 
         oldID = POTION_NAME_TO_ID.get(potionNameFromDamage((short) oldID));
-        return POTION_INDEX.containsKey(oldID) ? POTION_INDEX.get(oldID) : 0;
+        return (index = POTION_INDEX.get(oldID)) != null ? index : 0;
     }
 
     private static void registerEntity(Integer id, String name) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/metadata/MetaIndex.java

@@ -173,11 +173,7 @@ public enum MetaIndex {
 
     private static Optional<MetaIndex> getIndex(Entity1_10Types.EntityType type, int index) {
         Pair pair = new Pair<>(type, index);
-        if (metadataRewrites.containsKey(pair)) {
+        return Optional.fromNullable(metadataRewrites.get(pair));
-            return Optional.of(metadataRewrites.get(pair));
-        }
-
-        return Optional.absent();
     }
 
     public static MetaIndex searchIndex(Entity1_10Types.EntityType type, int index) {

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

@@ -5,6 +5,7 @@ import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.Pair;
 import us.myles.ViaVersion.api.Triple;
 import us.myles.ViaVersion.api.Via;
+import us.myles.ViaVersion.api.entities.Entity1_10Types;
 import us.myles.ViaVersion.api.minecraft.item.Item;
 import us.myles.ViaVersion.api.minecraft.metadata.Metadata;
 import us.myles.ViaVersion.api.protocol.Protocol;
@@ -184,8 +185,9 @@ public class EntityPackets {
                         List<Metadata> metadataList = wrapper.get(Types1_9.METADATA_LIST, 0);
                         int entityID = wrapper.get(Type.VAR_INT, 0);
                         EntityTracker tracker = wrapper.user().get(EntityTracker.class);
-                        if (tracker.getClientEntityTypes().containsKey(entityID)) {
+                        Entity1_10Types.EntityType type = tracker.getClientEntityTypes().get(entityID);
-                            MetadataRewriter.transform(tracker.getClientEntityTypes().get(entityID), metadataList);
+                        if (type != null) {
+                            MetadataRewriter.transform(type, metadataList);
                         } else {
                             // Buffer
                             tracker.addMetadataToBuffer(entityID, metadataList);

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

@@ -214,8 +214,9 @@ public class SpawnPackets {
                         List<Metadata> metadataList = wrapper.get(Types1_9.METADATA_LIST, 0);
                         int entityID = wrapper.get(Type.VAR_INT, 0);
                         EntityTracker tracker = wrapper.user().get(EntityTracker.class);
-                        if (tracker.getClientEntityTypes().containsKey(entityID)) {
+                        Entity1_10Types.EntityType type = tracker.getClientEntityTypes().get(entityID);
-                            MetadataRewriter.transform(tracker.getClientEntityTypes().get(entityID), metadataList);
+                        if (type != null) {
+                            MetadataRewriter.transform(type, metadataList);
                         } else {
                             Via.getPlatform().getLogger().warning("Unable to find entity for metadata, entity ID: " + entityID);
                             metadataList.clear();
@@ -319,8 +320,9 @@ public class SpawnPackets {
                         List<Metadata> metadataList = wrapper.get(Types1_9.METADATA_LIST, 0);
                         int entityID = wrapper.get(Type.VAR_INT, 0);
                         EntityTracker tracker = wrapper.user().get(EntityTracker.class);
-                        if (tracker.getClientEntityTypes().containsKey(entityID)) {
+                        Entity1_10Types.EntityType type = tracker.getClientEntityTypes().get(entityID);
-                            MetadataRewriter.transform(tracker.getClientEntityTypes().get(entityID), metadataList);
+                        if (type != null) {
+                            MetadataRewriter.transform(type, metadataList);
                         } else {
                             Via.getPlatform().getLogger().warning("Unable to find entity for metadata, entity ID: " + entityID);
                             metadataList.clear();

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/sounds/SoundEffect.java

@@ -284,9 +284,7 @@ public enum SoundEffect {
 
     public static SoundEffect getByName(String name) {
         name = name.toLowerCase();
-        if (effects.containsKey(name))
+        return effects.get(name);
-            return effects.get(name);
-        return null;
     }
 
 }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/CommandBlockStorage.java

@@ -25,8 +25,7 @@ public class CommandBlockStorage extends StoredObject {
 
     public void unloadChunk(int x, int z) {
         Pair<Integer, Integer> chunkPos = new Pair<>(x, z);
-        if (storedCommandBlocks.containsKey(chunkPos))
+        storedCommandBlocks.remove(chunkPos);
-            storedCommandBlocks.remove(chunkPos);
     }
 
     public void addOrUpdateBlock(Position position, CompoundTag tag) {
@@ -54,19 +53,18 @@ public class CommandBlockStorage extends StoredObject {
     public Optional<CompoundTag> getCommandBlock(Position position) {
         Pair<Integer, Integer> chunkCoords = getChunkCoords(position);
 
-        if (!storedCommandBlocks.containsKey(chunkCoords))
-            return Optional.absent();
-
         Map<Position, CompoundTag> blocks = storedCommandBlocks.get(chunkCoords);
-
+        if (blocks == null)
-        if (!blocks.containsKey(position))
             return Optional.absent();
 
-        CompoundTag tag = blocks.get(position).clone();
+        CompoundTag tag = blocks.get(position);
+        if (tag == null)
+            return Optional.absent();
+
+        tag = tag.clone();
         tag.put(new ByteTag("powered", (byte) 0));
         tag.put(new ByteTag("auto", (byte) 0));
         tag.put(new ByteTag("conditionMet", (byte) 0));
-
         return Optional.of(tag);
     }
 

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/EntityTracker.java

@@ -59,13 +59,13 @@ public class EntityTracker extends StoredObject {
     }
 
     public UUID getEntityUUID(int id) {
-        if (uuidMap.containsKey(id)) {
+        UUID uuid = uuidMap.get(id);
-            return uuidMap.get(id);
+        if (uuid == null) {
-        } else {
+            uuid = UUID.randomUUID();
-            UUID uuid = UUID.randomUUID();
             uuidMap.put(id, uuid);
-            return uuid;
         }
+
+        return uuid;
     }
 
     public void setSecondHand(Item item) {
@@ -117,11 +117,11 @@ public class EntityTracker extends StoredObject {
     }
 
     public void handleMetadata(int entityID, List<Metadata> metadataList) {
-        if (!clientEntityTypes.containsKey(entityID)) {
+        Entity1_10Types.EntityType type = clientEntityTypes.get(entityID);
+        if (type == null) {
             return;
         }
 
-        Entity1_10Types.EntityType type = clientEntityTypes.get(entityID);
         for (Metadata metadata : new ArrayList<>(metadataList)) {
             // Fix: wither (crash fix)
             if (type == Entity1_10Types.EntityType.WITHER) {
@@ -272,21 +272,23 @@ public class EntityTracker extends StoredObject {
     }
 
     public void addMetadataToBuffer(int entityID, List<Metadata> metadataList) {
-        if (metadataBuffer.containsKey(entityID)) {
+        final List<Metadata> metadata = metadataBuffer.get(entityID);
-            metadataBuffer.get(entityID).addAll(metadataList);
+        if (metadata != null) {
+            metadata.addAll(metadataList);
         } else {
             metadataBuffer.put(entityID, metadataList);
         }
     }
 
     public void sendMetadataBuffer(int entityID) {
-        if (metadataBuffer.containsKey(entityID)) {
+        List<Metadata> metadataList = metadataBuffer.get(entityID);
+        if (metadataList != null) {
             PacketWrapper wrapper = new PacketWrapper(0x39, null, getUser());
             wrapper.write(Type.VAR_INT, entityID);
-            wrapper.write(Types1_9.METADATA_LIST, metadataBuffer.get(entityID));
+            wrapper.write(Types1_9.METADATA_LIST, metadataList);
-            MetadataRewriter.transform(getClientEntityTypes().get(entityID), metadataBuffer.get(entityID));
+            MetadataRewriter.transform(getClientEntityTypes().get(entityID), metadataList);
-            handleMetadata(entityID, metadataBuffer.get(entityID));
+            handleMetadata(entityID, metadataList);
-            if (metadataBuffer.get(entityID).size() > 0) {
+            if (metadataList.size() > 0) {
                 try {
                     wrapper.send(Protocol1_9TO1_8.class);
                 } catch (Exception e) {

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

@@ -14,7 +14,7 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentSkipListMap;
 
 public abstract class Config implements ConfigurationProvider {
-    private static ThreadLocal<Yaml> yaml = new ThreadLocal<Yaml>() {
+    private static final ThreadLocal<Yaml> YAML = new ThreadLocal<Yaml>() {
         @Override
         protected Yaml initialValue() {
             DumperOptions options = new DumperOptions();
@@ -58,7 +58,7 @@ public abstract class Config implements ConfigurationProvider {
         Map<String, Object> config = null;
         if (location.exists()) {
             try (FileInputStream input = new FileInputStream(location)) {
-                config = (Map<String, Object>) yaml.get().load(input);
+                config = (Map<String, Object>) YAML.get().load(input);
             } catch (FileNotFoundException e) {
                 e.printStackTrace();
             } catch (IOException e) {
@@ -71,7 +71,7 @@ public abstract class Config implements ConfigurationProvider {
 
         Map<String, Object> defaults = config;
         try (InputStream stream = jarConfigFile.openStream()) {
-            defaults = (Map<String, Object>) yaml.get().load(stream);
+            defaults = (Map<String, Object>) YAML.get().load(stream);
             for (String option : unsupported) {
                 defaults.remove(option);
             }
@@ -97,7 +97,7 @@ public abstract class Config implements ConfigurationProvider {
 
     public synchronized void saveConfig(File location, Map<String, Object> config) {
         try {
-            commentStore.writeComments(yaml.get().dump(config), location);
+            commentStore.writeComments(YAML.get().dump(config), location);
         } catch (IOException e) {
             e.printStackTrace();
         }
@@ -128,33 +128,37 @@ public abstract class Config implements ConfigurationProvider {
     }
 
     public <T> T get(String key, Class<T> clazz, T def) {
-        if (this.config.containsKey(key)) {
+        Object o = this.config.get(key);
-            return (T) this.config.get(key);
+        if (o != null) {
+            return (T) o;
         } else {
             return def;
         }
     }
 
     public boolean getBoolean(String key, boolean def) {
-        if (this.config.containsKey(key)) {
+        Object o = this.config.get(key);
-            return (boolean) this.config.get(key);
+        if (o != null) {
+            return (boolean) o;
         } else {
             return def;
         }
     }
 
     public String getString(String key, String def) {
-        if (this.config.containsKey(key)) {
+        final Object o = this.config.get(key);
-            return (String) this.config.get(key);
+        if (o != null) {
+            return (String) o;
         } else {
             return def;
         }
     }
 
     public int getInt(String key, int def) {
-        if (this.config.containsKey(key)) {
+        Object o = this.config.get(key);
-            if (this.config.get(key) instanceof Number) {
+        if (o != null) {
-                return ((Number) this.config.get(key)).intValue();
+            if (o instanceof Number) {
+                return ((Number) o).intValue();
             } else {
                 return def;
             }
@@ -164,9 +168,10 @@ public abstract class Config implements ConfigurationProvider {
     }
 
     public double getDouble(String key, double def) {
-        if (this.config.containsKey(key)) {
+        Object o = this.config.get(key);
-            if (this.config.get(key) instanceof Number) {
+        if (o != null) {
-                return ((Number) this.config.get(key)).doubleValue();
+            if (o instanceof Number) {
+                return ((Number) o).doubleValue();
             } else {
                 return def;
             }
@@ -176,8 +181,9 @@ public abstract class Config implements ConfigurationProvider {
     }
 
     public List<Integer> getIntegerList(String key) {
-        if (this.config.containsKey(key)) {
+        Object o = this.config.get(key);
-            return (List<Integer>) this.config.get(key);
+        if (o != null) {
+            return (List<Integer>) o;
         } else {
             return new ArrayList<>();
         }