添加半包解码handler解决粘包问题

Author: yimkong

src/main/java/TimeClient.java

@@ -5,6 +5,8 @@
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.LineBasedFrameDecoder;
+import io.netty.handler.codec.string.StringDecoder;
 
 /**
  * author yg
@@ -22,6 +24,8 @@ private void connect(int port, String host) throws Exception {
                     .handler(new ChannelInitializer<SocketChannel>() {
                         @Override
                         protected void initChannel(SocketChannel ch) throws Exception {
+                            ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
+                            ch.pipeline().addLast(new StringDecoder());
                             ch.pipeline().addLast(new TimeClientHandler());
                         }
                     });
@@ -33,8 +37,12 @@ protected void initChannel(SocketChannel ch) throws Exception {
 
     }
 
-    public static void main(String[] args) throws Exception {
+    public static void main(String[] args) {
         int port = 8080;
-        new TimeClient().connect(port,"localhost");
+        try {
+            new TimeClient().connect(port,"localhost");
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
     }
 }

src/main/java/TimeClientHandler.java

@@ -3,8 +3,6 @@
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
 
-import java.nio.charset.StandardCharsets;
-
 /**
  * author yg
  * description
@@ -30,10 +28,7 @@ public void channelActive(ChannelHandlerContext ctx) throws Exception {
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-        ByteBuf byteBuf = (ByteBuf) msg;
-        byte[] req = new byte[byteBuf.readableBytes()];
-        byteBuf.readBytes(req);
-        String body = new String(req, StandardCharsets.UTF_8);
+        String body = (String) msg;
         System.out.println("body:" + body + ",counter:" + ++counter);
     }
 

src/main/java/TimeServer.java

@@ -5,6 +5,8 @@
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.handler.codec.LineBasedFrameDecoder;
+import io.netty.handler.codec.string.StringDecoder;
 
 /**
  * author yg
@@ -34,6 +36,8 @@ private class ChildChannelHandler extends ChannelInitializer<SocketChannel> {
 
         @Override
         protected void initChannel(SocketChannel ch) throws Exception {
+            ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
+            ch.pipeline().addLast(new StringDecoder());
             ch.pipeline().addLast(new TimeServerHandler());
         }
     }

src/main/java/TimeServerHandler.java

@@ -3,7 +3,6 @@
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
 
-import java.nio.charset.StandardCharsets;
 import java.util.Date;
 
 /**
@@ -16,10 +15,7 @@ public class TimeServerHandler extends ChannelInboundHandlerAdapter {
 
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-        ByteBuf byteBuf = (ByteBuf) msg;
-        byte[] req = new byte[byteBuf.readableBytes()];
-        byteBuf.readBytes(req);
-        String body = new String(req, StandardCharsets.UTF_8).substring(0, req.length - System.getProperty(Constant.SEP).length());
+        String body = (String) msg;
         System.out.println("receive:" + body + ",counter:" + ++counter);
         String time = Constant.REQ.equalsIgnoreCase(body) ? new Date().toString() : Constant.BAD_REQ;
         time = time + System.getProperty(Constant.SEP);
@@ -29,6 +25,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        cause.printStackTrace();
         ctx.close();
     }
 }