TCP以流的方式進行數據傳輸，上層應用協議爲了對消息的區分，採用了以下幾種方法。
1.消息固定長度
2.第一篇講的回車換行符形式
3.以特殊字符作爲消息結束符的形式
4.通過消息頭中定義長度字段來標識消息的總長度
一、採用指定分割符解決粘包與拆包問題
服務端
1 package com.ming.netty.nio.stickpack; 2 3 4 5 import java.net.InetSocketAddress; 6 7 import io.netty.bootstrap.ServerBootstrap; 8 import io.netty.buffer.ByteBuf; 9 import io.netty.buffer.Unpooled; 10 import io.netty.channel.ChannelFuture; 11 import io.netty.channel.ChannelInitializer; 12 import io.netty.channel.ChannelOption; 13 import io.netty.channel.EventLoopGroup; 14 import io.netty.channel.nio.NioEventLoopGroup; 15 import io.netty.channel.socket.SocketChannel; 16 import io.netty.channel.socket.nio.NioServerSocketChannel; 17 import io.netty.handler.codec.DelimiterBasedFrameDecoder; 18 import io.netty.handler.codec.string.StringDecoder; 19 import io.netty.handler.logging.LogLevel; 20 import io.netty.handler.logging.LoggingHandler; 21 22 public class EchoServer { 23 24 public void bind(String addr,int port) throws Exception{ 25 EventLoopGroup bossGroup=new NioEventLoopGroup(); 26 EventLoopGroup workGroup=new NioEventLoopGroup(); 27 try { 28 ServerBootstrap server=new ServerBootstrap(); 29 server.group(bossGroup,workGroup) 30 .channel(NioServerSocketChannel.class) 31 .option(ChannelOption.SO_BACKLOG, 100) 32 .handler(new LoggingHandler(LogLevel.INFO)) 33 .childHandler(new ChannelInitializer<SocketChannel>() { 34 35 @Override 36 protected void initChannel(SocketChannel sc) throws Exception { 37 ByteBuf delimiter=Unpooled.copiedBuffer("$_".getBytes());//指定消息分割符處理數據 38 sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, delimiter));//如果取消了分割符解碼，就會出現TCP粘包之類的問題了 39 sc.pipeline().addLast(new StringDecoder()); 40 sc.pipeline().addLast(new EchoServerHandler()); 41 42 } 43 44 }); 45 ChannelFuture f=server.bind(new InetSocketAddress(addr, port)).sync(); 46 System.out.println("啓動服務器:"+f.channel().localAddress()); 47 //等等服務器端監聽端口關閉 48 f.channel().closeFuture().sync(); 49 } catch (Exception e) { 50 e.printStackTrace(); 51 }finally{ 52 bossGroup.shutdownGracefully(); 53 workGroup.shutdownGracefully(); 54 } 55 } 56 57 58 public static void main(String[] args) throws Exception{ 59 new EchoServer().bind("192.168.1.108", 8500); 60 } 61 62 }
1 package com.ming.netty.nio.stickpack; 2 3 import io.netty.buffer.ByteBuf; 4 import io.netty.buffer.Unpooled; 5 import io.netty.channel.ChannelHandlerAdapter; 6 import io.netty.channel.ChannelHandlerContext; 7 8 public class EchoServerHandler extends ChannelHandlerAdapter{ 9 10 int count=0; 11 12 @Override 13 public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 14 15 String body=(String)msg; 16 System.out.println("服務器收到"+(++count)+"次客戶端消息，消息是:"+body); 17 body+="$_"; 18 ByteBuf rep=Unpooled.copiedBuffer(body.getBytes()); 19 ctx.writeAndFlush(rep); 20 } 21 22 @Override 23 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { 24 cause.printStackTrace(); 25 ctx.close(); 26 } 27 28 29 }
客服端:
1 package com.ming.netty.nio.stickpack; 2 3 import java.net.InetSocketAddress; 4 5 import io.netty.bootstrap.Bootstrap; 6 import io.netty.buffer.ByteBuf; 7 import io.netty.buffer.Unpooled; 8 import io.netty.channel.ChannelFuture; 9 import io.netty.channel.ChannelInitializer; 10 import io.netty.channel.ChannelOption; 11 import io.netty.channel.EventLoopGroup; 12 import io.netty.channel.nio.NioEventLoopGroup; 13 import io.netty.channel.socket.SocketChannel; 14 import io.netty.channel.socket.nio.NioSocketChannel; 15 import io.netty.handler.codec.DelimiterBasedFrameDecoder; 16 import io.netty.handler.codec.string.StringDecoder; 17 18 public class EchoClient { 19 20 public void connect(String addr,int port) throws Exception{ 21 EventLoopGroup workGroup=new NioEventLoopGroup(); 22 try { 23 Bootstrap b=new Bootstrap(); 24 b.group(workGroup) 25 .channel(NioSocketChannel.class) 26 .option(ChannelOption.TCP_NODELAY, true) 27 .handler(new ChannelInitializer<SocketChannel>() { 28 29 @Override 30 protected void initChannel(SocketChannel sc) throws Exception { 31 ByteBuf delimiter=Unpooled.copiedBuffer("$_".getBytes());//指定消息分割符 32 sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, delimiter)); 33 sc.pipeline().addLast(new StringDecoder()); 34 sc.pipeline().addLast(new EchoClientHandler()); 35 } 36 37 }); 38 39 ChannelFuture f=b.connect(new InetSocketAddress(addr, port)).sync(); 40 System.out.println("連接服務器:"+f.channel().remoteAddress()+",本地地址:"+f.channel().localAddress()); 41 f.channel().closeFuture().sync();//等待客戶端關閉連接 42 43 } catch (Exception e) { 44 e.printStackTrace(); 45 }finally{ 46 workGroup.shutdownGracefully(); 47 } 48 } 49 50 public static void main(String[] args) throws Exception{ 51 new EchoClient().connect("192.168.1.108", 8500); 52 } 53 }
1 package com.ming.netty.nio.stickpack; 2 3 import io.netty.buffer.Unpooled; 4 import io.netty.channel.ChannelHandlerAdapter; 5 import io.netty.channel.ChannelHandlerContext; 6 7 public class EchoClientHandler extends ChannelHandlerAdapter{ 8 9 int count=0; 10 11 static final String REQUEST_TEST_DATA="I love you....$_"; 12 13 14 15 @Override 16 public void channelActive(ChannelHandlerContext ctx) throws Exception { 17 //發送消息,模擬發送向服務端發送1000條數據 18 for(int i=0,j=1000;i<j;i++){ 19 ctx.writeAndFlush(Unpooled.copiedBuffer(REQUEST_TEST_DATA.getBytes())); 20 } 21 } 22 23 @Override 24 public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 25 String sendMsg=(String)msg; 26 System.out.println("客戶端發送給服務器的次數:"+(++count)+"，服務器接收數據爲："+sendMsg); 27 } 28 29 30 31 @Override 32 public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { 33 ctx.flush(); 34 } 35 36 @Override 37 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { 38 cause.printStackTrace(); 39 ctx.close(); 40 } 41 42 43 }
很多事情看代碼解決，hello world!
下篇打算寫定長解碼了...最後寫一下通過消息頭中定義長度字段來標識消息的總長度來解碼玩玩....
感覺可以點個贊吧,好自戀一把