#3104: Use lambdas rather than reflection to create packets

protocol/src/main/java/net/md_5/bungee/protocol/Protocol.java

@@ -6,7 +6,7 @@ import gnu.trove.map.TIntObjectMap;
 import gnu.trove.map.TObjectIntMap;
 import gnu.trove.map.hash.TIntObjectHashMap;
 import gnu.trove.map.hash.TObjectIntHashMap;
-import java.lang.reflect.Constructor;
+import java.util.function.Supplier;
 import lombok.Data;
 import lombok.Getter;
 import net.md_5.bungee.protocol.packet.BossBar;
@@ -55,6 +55,7 @@ public enum Protocol
         {
             TO_SERVER.registerPacket(
                     Handshake.class,
+                    Handshake::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 )
             );
         }
@@ -66,6 +67,7 @@ public enum Protocol
         {
             TO_CLIENT.registerPacket(
                     KeepAlive.class,
+                    KeepAlive::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x1F ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x21 ),
@@ -77,6 +79,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Login.class,
+                    Login::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x01 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x23 ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x25 ),
@@ -87,6 +90,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Chat.class,
+                    Chat::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x02 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x0F ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x0E ),
@@ -96,6 +100,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Respawn.class,
+                    Respawn::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x07 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x33 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x34 ),
@@ -109,6 +114,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     BossBar.class,
+                    BossBar::new,
                     map( ProtocolConstants.MINECRAFT_1_9, 0x0C ),
                     map( ProtocolConstants.MINECRAFT_1_15, 0x0D ),
                     map( ProtocolConstants.MINECRAFT_1_16, 0x0C ),
@@ -116,6 +122,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     PlayerListItem.class, // PlayerInfo
+                    PlayerListItem::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x38 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x2D ),
                     map( ProtocolConstants.MINECRAFT_1_12_1, 0x2E ),
@@ -128,6 +135,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     TabCompleteResponse.class,
+                    TabCompleteResponse::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x3A ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x0E ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x10 ),
@@ -138,6 +146,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     ScoreboardObjective.class,
+                    ScoreboardObjective::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x3B ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x3F ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x41 ),
@@ -149,6 +158,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     ScoreboardScore.class,
+                    ScoreboardScore::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x3C ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x42 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x44 ),
@@ -160,6 +170,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     ScoreboardDisplay.class,
+                    ScoreboardDisplay::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x3D ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x38 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x3A ),
@@ -171,6 +182,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Team.class,
+                    Team::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x3E ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x41 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x43 ),
@@ -182,6 +194,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     PluginMessage.class,
+                    PluginMessage::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x3F ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x18 ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x19 ),
@@ -193,6 +206,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Kick.class,
+                    Kick::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x40 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x1A ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x1B ),
@@ -204,6 +218,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Title.class,
+                    Title::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x45 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x47 ),
                     map( ProtocolConstants.MINECRAFT_1_12_1, 0x48 ),
@@ -213,18 +228,24 @@ public enum Protocol
                     map( ProtocolConstants.MINECRAFT_1_16, 0x4F ),
                     map( ProtocolConstants.MINECRAFT_1_17, 0x59 )
             );
-            TO_CLIENT.registerPacket( ClearTitles.class,
+            TO_CLIENT.registerPacket(
+                    ClearTitles.class,
+                    ClearTitles::new,
                     map( ProtocolConstants.MINECRAFT_1_17, 0x10 )
             );
             TO_CLIENT.registerPacket(
                     Subtitle.class,
+                    Subtitle::new,
                     map( ProtocolConstants.MINECRAFT_1_17, 0x57 )
             );
-            TO_CLIENT.registerPacket( TitleTimes.class,
+            TO_CLIENT.registerPacket(
+                    TitleTimes.class,
+                    TitleTimes::new,
                     map( ProtocolConstants.MINECRAFT_1_17, 0x5A )
             );
             TO_CLIENT.registerPacket(
                     PlayerListHeaderFooter.class,
+                    PlayerListHeaderFooter::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x47 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x48 ),
                     map( ProtocolConstants.MINECRAFT_1_9_4, 0x47 ),
@@ -238,6 +259,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     EntityStatus.class,
+                    EntityStatus::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x1A ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x1B ),
                     map( ProtocolConstants.MINECRAFT_1_13, 0x1C ),
@@ -249,6 +271,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     Commands.class,
+                    Commands::new,
                     map( ProtocolConstants.MINECRAFT_1_13, 0x11 ),
                     map( ProtocolConstants.MINECRAFT_1_15, 0x12 ),
                     map( ProtocolConstants.MINECRAFT_1_16, 0x11 ),
@@ -257,6 +280,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     GameState.class,
+                    GameState::new,
                     map( ProtocolConstants.MINECRAFT_1_15, 0x1F ),
                     map( ProtocolConstants.MINECRAFT_1_16, 0x1E ),
                     map( ProtocolConstants.MINECRAFT_1_16_2, 0x1D ),
@@ -264,6 +288,7 @@ public enum Protocol
             );
             TO_CLIENT.registerPacket(
                     ViewDistance.class,
+                    ViewDistance::new,
                     map( ProtocolConstants.MINECRAFT_1_14, 0x41 ),
                     map( ProtocolConstants.MINECRAFT_1_15, 0x42 ),
                     map( ProtocolConstants.MINECRAFT_1_16, 0x41 ),
@@ -272,6 +297,7 @@ public enum Protocol
 
             TO_SERVER.registerPacket(
                     KeepAlive.class,
+                    KeepAlive::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x0B ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x0C ),
@@ -283,6 +309,7 @@ public enum Protocol
             );
             TO_SERVER.registerPacket(
                     Chat.class,
+                    Chat::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x01 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x02 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x03 ),
@@ -291,6 +318,7 @@ public enum Protocol
             );
             TO_SERVER.registerPacket(
                     TabCompleteRequest.class,
+                    TabCompleteRequest::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x14 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x01 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x02 ),
@@ -300,6 +328,7 @@ public enum Protocol
             );
             TO_SERVER.registerPacket(
                     ClientSettings.class,
+                    ClientSettings::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x15 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x04 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x05 ),
@@ -308,6 +337,7 @@ public enum Protocol
             );
             TO_SERVER.registerPacket(
                     PluginMessage.class,
+                    PluginMessage::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x17 ),
                     map( ProtocolConstants.MINECRAFT_1_9, 0x09 ),
                     map( ProtocolConstants.MINECRAFT_1_12, 0x0A ),
@@ -325,19 +355,23 @@ public enum Protocol
         {
             TO_CLIENT.registerPacket(
                     StatusResponse.class,
+                    StatusResponse::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 )
             );
             TO_CLIENT.registerPacket(
                     PingPacket.class,
+                    PingPacket::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x01 )
             );
 
             TO_SERVER.registerPacket(
                     StatusRequest.class,
+                    StatusRequest::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 )
             );
             TO_SERVER.registerPacket(
                     PingPacket.class,
+                    PingPacket::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x01 )
             );
         }
@@ -349,35 +383,43 @@ public enum Protocol
         {
             TO_CLIENT.registerPacket(
                     Kick.class,
+                    Kick::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 )
             );
             TO_CLIENT.registerPacket(
                     EncryptionRequest.class,
+                    EncryptionRequest::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x01 )
             );
             TO_CLIENT.registerPacket(
                     LoginSuccess.class,
+                    LoginSuccess::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x02 )
             );
             TO_CLIENT.registerPacket(
                     SetCompression.class,
+                    SetCompression::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x03 )
             );
             TO_CLIENT.registerPacket(
                     LoginPayloadRequest.class,
+                    LoginPayloadRequest::new,
                     map( ProtocolConstants.MINECRAFT_1_13, 0x04 )
             );
 
             TO_SERVER.registerPacket(
                     LoginRequest.class,
+                    LoginRequest::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x00 )
             );
             TO_SERVER.registerPacket(
                     EncryptionResponse.class,
+                    EncryptionResponse::new,
                     map( ProtocolConstants.MINECRAFT_1_8, 0x01 )
             );
             TO_SERVER.registerPacket(
                     LoginPayloadResponse.class,
+                    LoginPayloadResponse::new,
                     map( ProtocolConstants.MINECRAFT_1_13, 0x02 )
             );
         }
@@ -428,7 +470,8 @@ public enum Protocol
 
         private final int protocolVersion;
         private final TObjectIntMap<Class<? extends DefinedPacket>> packetMap = new TObjectIntHashMap<>( MAX_PACKET_ID );
-        private final Constructor<? extends DefinedPacket>[] packetConstructors = new Constructor[ MAX_PACKET_ID ];
+        @SuppressWarnings("unchecked")
+        private final Supplier<? extends DefinedPacket>[] packetConstructors = new Supplier[ MAX_PACKET_ID ];
     }
 
     @Data
@@ -484,25 +527,15 @@ public enum Protocol
             }
             if ( id > MAX_PACKET_ID )
             {
-                throw new BadPacketException( "Packet with id " + id + " outside of range " );
+                throw new BadPacketException( "Packet with id " + id + " outside of range" );
             }
 
-            Constructor<? extends DefinedPacket> constructor = protocolData.packetConstructors[id];
+            Supplier<? extends DefinedPacket> constructor = protocolData.packetConstructors[id];
-            try
+            return ( constructor == null ) ? null : constructor.get();
-            {
-                return ( constructor == null ) ? null : constructor.newInstance();
-            } catch ( ReflectiveOperationException ex )
-            {
-                throw new BadPacketException( "Could not construct packet with id " + id, ex );
-            }
         }
 
-        private void registerPacket(Class<? extends DefinedPacket> packetClass, ProtocolMapping... mappings)
+        private void registerPacket(Class<? extends DefinedPacket> packetClass, Supplier<? extends DefinedPacket> constructor, ProtocolMapping... mappings)
         {
-            try
-            {
-                Constructor<? extends DefinedPacket> constructor = packetClass.getDeclaredConstructor();
-
             int mappingIndex = 0;
             ProtocolMapping mapping = mappings[mappingIndex];
             for ( int protocol : ProtocolConstants.SUPPORTED_VERSION_IDS )
@@ -530,10 +563,6 @@ public enum Protocol
                 data.packetMap.put( packetClass, mapping.packetID );
                 data.packetConstructors[mapping.packetID] = constructor;
             }
-            } catch ( NoSuchMethodException ex )
-            {
-                throw new BadPacketException( "No NoArgsConstructor for packet class " + packetClass );
-            }
         }
 
         final int getId(Class<? extends DefinedPacket> packet, int version)