refactory

src/main/java/mc/core/NotSupportException.java

@@ -0,0 +1,8 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-25
+ */
+package mc.core;
+
+public class NotSupportException extends RuntimeException {
+}

src/main/java/mc/core/Packet.java

@@ -0,0 +1,10 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-25
+ */
+package mc.core;
+
+public interface Packet {
+    int getSize();
+    int getId();
+}

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

@@ -7,23 +7,46 @@ package mc.core.netty;
 import io.netty.buffer.ByteBuf;
 import lombok.Getter;
 import lombok.ToString;
+import mc.core.NotSupportException;
 
-import static mc.core.netty.Utilits.*;
+import static mc.core.netty.Utils.*;
 
 @Getter
 @ToString
-public class HandshakeRequestPacket extends BasePacket {
-    private final int protocolVersion;
-    private final String serverAddress;
-    private final int serverPort;
-    private final int nextState;
+public class HandshakeRequestPacket implements NettyPacket {
+    private static final int id = 0;
+    private int protocolVersion;
+    private String serverAddress;
+    private int serverPort;
+    private int nextState;
+    private int size;
 
-    public HandshakeRequestPacket(int length, int id, ByteBuf byteBuf) throws Exception {
-        super(length, id);
+    @Override
+    public void writeSelf(ByteBuf byteBuf) {
+        throw new NotSupportException();
+    }
 
+    @Override
+    public void fillFromByteBuf(ByteBuf byteBuf) {
         protocolVersion = readVarInt(byteBuf);
         serverAddress = readString(byteBuf);
         serverPort = readUnsignedShort(byteBuf);
         nextState = readVarInt(byteBuf);
+
+        size = lengthVarInt(id)
+                + lengthVarInt(protocolVersion)
+                + lengthString(serverAddress)
+                + lengthVarInt(serverPort)
+                + lengthVarInt(nextState);
+    }
+
+    @Override
+    public int getSize() {
+        return size;
+    }
+
+    @Override
+    public int getId() {
+        return id;
     }
 }

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

@@ -6,11 +6,14 @@ package mc.core.netty;
 
 import com.google.gson.JsonObject;
 import io.netty.buffer.ByteBuf;
+import mc.core.NotSupportException;
 
-import static mc.core.netty.Utilits.lengthVarInt;
+import static mc.core.netty.Utils.*;
 
-public class HandshakeResponsePacket extends BasePacket {
+public class HandshakeResponsePacket implements NettyPacket {
+    private static final int id = 0;
     private static String json;
+    private static int size;
 
     static {
         JsonObject versionObj = new JsonObject();
@@ -30,19 +33,30 @@ public class HandshakeResponsePacket extends BasePacket {
         rootObj.add("description", descriptionObj);
 
         json = rootObj.toString();
-    }
 
-    public HandshakeResponsePacket(int length, int id) {
-        super(length, id);
+        size = lengthVarInt(id)
+                + lengthString(json);
     }
 
     @Override
     public void writeSelf(ByteBuf byteBuf) {
-        Utilits.writeString(json, byteBuf);
+        writeVarInt(getSize(), byteBuf);
+        writeVarInt(getId(), byteBuf);
+        writeString(json, byteBuf);
     }
 
     @Override
-    public int getLength() {
-        return lengthVarInt(getId()) + lengthVarInt(json.length()) + json.length();
+    public void fillFromByteBuf(ByteBuf byteBuf) {
+        throw new NotSupportException();
+    }
+
+    @Override
+    public int getSize() {
+        return size;
+    }
+
+    @Override
+    public int getId() {
+        return id;
     }
 }

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

@@ -0,0 +1,13 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-03-25
+ */
+package mc.core.netty;
+
+import io.netty.buffer.ByteBuf;
+import mc.core.Packet;
+
+public interface NettyPacket extends Packet {
+    void writeSelf(ByteBuf byteBuf);
+    void fillFromByteBuf(ByteBuf byteBuf);
+}

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

@@ -10,18 +10,20 @@ import io.netty.handler.codec.ReplayingDecoder;
 
 import java.util.List;
 
-import static mc.core.netty.Utilits.readVarInt;
+import static mc.core.netty.Utils.readVarInt;
 
-public class PacketDecoder extends ReplayingDecoder<BasePacket> {
+public class PacketDecoder extends ReplayingDecoder<NettyPacket> {
     @Override
     protected void decode(ChannelHandlerContext context, ByteBuf byteBuf, List<Object> list) throws Exception {
         int length = readVarInt(byteBuf);
         int id = readVarInt(byteBuf);
 
         if (id == 0) {
-            list.add(new HandshakeRequestPacket(length, id, byteBuf));
+            NettyPacket packet = new HandshakeRequestPacket();
+            packet.fillFromByteBuf(byteBuf);
+            list.add(packet);
         } else {
-            list.add(new BasePacket(length, id));
+            list.add(new UnknownPacket(length, id));
             byteBuf.skipBytes(length);
         }
     }

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

@@ -8,13 +8,9 @@ import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
 
-import static mc.core.netty.Utilits.writeVarInt;
-
-public class PacketEncoder extends MessageToByteEncoder<BasePacket> {
+public class PacketEncoder extends MessageToByteEncoder<NettyPacket> {
     @Override
-    protected void encode(ChannelHandlerContext context, BasePacket packet, ByteBuf byteBuf) throws Exception {
-        writeVarInt(packet.getLength(), byteBuf);
-        writeVarInt(packet.getId(), byteBuf);
+    protected void encode(ChannelHandlerContext context, NettyPacket packet, ByteBuf byteBuf) throws Exception {
         packet.writeSelf(byteBuf);
     }
 }

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

@@ -8,16 +8,18 @@ import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.SimpleChannelInboundHandler;
 import lombok.extern.slf4j.Slf4j;
 
+import static mc.core.netty.Utils.equalsPacket;
+
 @Slf4j
-public class PacketHandler extends SimpleChannelInboundHandler<BasePacket> {
+public class PacketHandler extends SimpleChannelInboundHandler<NettyPacket> {
     @Override
-    protected void channelRead0(ChannelHandlerContext context, BasePacket packet) throws Exception {
+    protected void channelRead0(ChannelHandlerContext context, NettyPacket packet) throws Exception {
         log.info("Packet: {} | Data: {}",
                 packet.getClass().getSimpleName(),
                 packet.toString());
 
-        if (packet.getClass().getSimpleName().equals("HandshakeRequestPacket")) {
-            context.channel().writeAndFlush(new HandshakeResponsePacket(0, 0));
+        if (equalsPacket(packet, "HandshakeRequestPacket")) {
+            context.channel().writeAndFlush(new HandshakeResponsePacket());
         }
     }
 }

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

@@ -8,17 +8,26 @@ import io.netty.buffer.ByteBuf;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
-import lombok.extern.slf4j.Slf4j;
+import mc.core.NotSupportException;
 
 @RequiredArgsConstructor
 @Getter
 @ToString
-@Slf4j
-class BasePacket {
+class UnknownPacket implements NettyPacket {
     private final int length;
     private final int id;
 
     public void writeSelf(ByteBuf byteBuf) {
-        log.warn("write not support");
+        throw new NotSupportException();
+    }
+
+    @Override
+    public void fillFromByteBuf(ByteBuf byteBuf) {
+        throw new NotSupportException();
+    }
+
+    @Override
+    public int getSize() {
+        return length;
     }
 }

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

@@ -5,11 +5,13 @@
 package mc.core.netty;
 
 import io.netty.buffer.ByteBuf;
+import lombok.extern.slf4j.Slf4j;
 
 import java.nio.charset.StandardCharsets;
 
-public class Utilits {
-    public static int readVarInt(ByteBuf byteBuf) throws Exception {
+@Slf4j
+public class Utils {
+    public static int readVarInt(ByteBuf byteBuf) {
         int result = 0;
         byte read;
         int numRead = 0;
@@ -21,7 +23,8 @@ public class Utilits {
 
             numRead++;
             if (numRead > 5) {
-                throw new Exception("VarInt is too big");
+                log.warn("VarInt is too big");
+                break;
             }
         } while ((read & 0b10000000) != 0);
 
@@ -51,7 +54,11 @@ public class Utilits {
         return result;
     }
 
-    public static String readString(ByteBuf byteBuf) throws Exception {
+    public static int lengthString(String value) {
+        return lengthVarInt(value.length()) + value.length();
+    }
+
+    public static String readString(ByteBuf byteBuf) {
         int length = readVarInt(byteBuf);
         byte[] buffer = new byte[length];
         int i = 0;
@@ -70,4 +77,8 @@ public class Utilits {
         writeVarInt(value.length(), byteBuf);
         byteBuf.writeBytes(value.getBytes());
     }
+
+    public static boolean equalsPacket(NettyPacket packet, String name) {
+        return packet.getClass().getSimpleName().equals(name);
+    }
 }