State

src/main/java/mc/core/netty/HandshakeRequestPacket.java

@@ -9,6 +9,8 @@ import lombok.Getter;
 import lombok.ToString;
 import mc.core.NotSupportException;
 
+import java.util.Optional;
+
 import static mc.core.netty.Utils.*;
 
 @Getter
@@ -18,7 +20,7 @@ public class HandshakeRequestPacket implements NettyPacket {
     private int protocolVersion;
     private String serverAddress;
     private int serverPort;
-    private int nextState;
+    private State nextState;
     private int size;
 
     @Override
@@ -31,13 +33,14 @@ public class HandshakeRequestPacket implements NettyPacket {
         protocolVersion = readVarInt(byteBuf);
         serverAddress = readString(byteBuf);
         serverPort = readUnsignedShort(byteBuf);
-        nextState = readVarInt(byteBuf);
+        final int nextStateInt = readVarInt(byteBuf);
+        nextState = State.getById(nextStateInt).orElseThrow(() -> new UnknowState(nextStateInt));
 
         size = lengthVarInt(id)
                 + lengthVarInt(protocolVersion)
                 + lengthString(serverAddress)
                 + lengthVarInt(serverPort)
-                + lengthVarInt(nextState);
+                + lengthVarInt(nextState.getId());
     }
 
     @Override

src/main/java/mc/core/netty/PacketDecoder.java

@@ -9,6 +9,7 @@ import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ReplayingDecoder;
 
 import java.util.List;
+import java.util.Optional;
 
 import static mc.core.netty.Utils.readVarInt;
 
@@ -18,8 +19,10 @@ public class PacketDecoder extends ReplayingDecoder<NettyPacket> {
         int length = readVarInt(byteBuf);
         int id = readVarInt(byteBuf);
 
-        if (id == 0) {
-            NettyPacket packet = new HandshakeRequestPacket();
+        Optional<Class<? extends NettyPacket>> packetClass = context.channel().attr(State.ATTR_STATE).get().getPacketClass(id);
+
+        if (packetClass.isPresent()) {
+            NettyPacket packet = packetClass.get().newInstance();
             packet.fillFromByteBuf(byteBuf);
             list.add(packet);
         } else {

src/main/java/mc/core/netty/PacketHandler.java

@@ -12,6 +12,11 @@ import static mc.core.netty.Utils.equalsPacket;
 
 @Slf4j
 public class PacketHandler extends SimpleChannelInboundHandler<NettyPacket> {
+    @Override
+    public void channelActive(ChannelHandlerContext context) throws Exception {
+        context.channel().attr(State.ATTR_STATE).set(State.Handshaking);
+    }
+
     @Override
     protected void channelRead0(ChannelHandlerContext context, NettyPacket packet) throws Exception {
         log.info("Packet: {} | Data: {}",

src/main/java/mc/core/netty/State.java

@@ -0,0 +1,36 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-25
+ */
+package mc.core.netty;
+
+import com.google.common.collect.ImmutableMap;
+import io.netty.util.AttributeKey;
+import lombok.Getter;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.Optional;
+
+public enum State {
+    Handshaking(1, ImmutableMap.of(0, HandshakeRequestPacket.class));
+
+    public static final AttributeKey<State> ATTR_STATE = AttributeKey.newInstance("ATTR_STATE");
+
+    public static Optional<State> getById(final int id) {
+        return Arrays.stream(State.values()).filter(state -> state.id == id).findFirst();
+    }
+
+    @Getter
+    private final int id;
+    private final Map<Integer, Class<? extends NettyPacket>> requestMap;
+
+    State(int id, Map<Integer, Class<? extends NettyPacket>> requestMap) {
+        this.id = id;
+        this.requestMap = requestMap;
+    }
+
+    public Optional<Class<? extends NettyPacket>> getPacketClass(int id) {
+        return Optional.ofNullable(requestMap.get(id));
+    }
+}

src/main/java/mc/core/netty/UnknowState.java

@@ -0,0 +1,11 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-26
+ */
+package mc.core.netty;
+
+public class UnknowState extends RuntimeException {
+    public UnknowState(int numberOfState) {
+        super("Unknown state: " + numberOfState);
+    }
+}