Netty: TCP服务器和客户端解决粘包问题

Netty: TCP服务器和客户端解决粘包问题

1.服务器端pom.xml

    4.0.0

    cn.edu.tju
    nettyechoserver
    1.0-SNAPSHOT
    
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    8
                    8
                
            

        
    
    
        
        
            io.netty
            netty-all
            4.0.0.Final
        

        
        
            com.google.protobuf
            protobuf-java
            3.0.0
        




    

2.服务器端ChannelHandler

package cn.edu.tju.handler;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandler;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelPipeline;

import java.util.Date;

public class ServerChannelHandler extends ChannelInboundHandlerAdapter {
    private int counter=0;
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        String msg="message from server: "+new Date().toLocaleString();
        ByteBuf message=Unpooled.copiedBuffer(msg.getBytes());
        //ctx.writeAndFlush(message);
    }





    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        String str=(String)msg;
        String sequence=String.valueOf(++counter)+" : ";
        System.out.println(sequence+str);
    }

    @Override
    public  void exceptionCaught(ChannelHandlerContext ctx,Throwable cause){
        System.out.println(cause.getMessage());
    }
}

3.服务器端主类：

package cn.edu.tju;

import cn.edu.tju.handler.ServerChannelHandler;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LinebasedframeDecoder;
import io.netty.handler.codec.string.StringDecoder;

public class Start {
    private static int port=8899;
    public static void main(String[] args) {
        EventLoopGroup bossGroup=new NioEventLoopGroup();
        EventLoopGroup workerGroup=new NioEventLoopGroup();
        try{
            ServerBootstrap serverBootstrap=new ServerBootstrap();
            serverBootstrap.group(bossGroup,workerGroup).
                    channel(NioServerSocketChannel.class).
                    childHandler(new ChannelInitializer() {
                        @Override
                        protected void initChannel(Channel ch) throws Exception {
                            //以下三个ChannelHandler的顺序不能改变
                            ch.pipeline().addLast(new LinebasedframeDecoder(1024));
                            ch.pipeline().addLast(new StringDecoder());
                            ch.pipeline().addLast(new ServerChannelHandler());
                        }
                    });


            ChannelFuture channelFuture=serverBootstrap.bind(port).sync();
            channelFuture.channel().closeFuture().sync();
        }catch (Exception ex){
            System.out.println(ex.getMessage());
        }finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }


    }
}

4.客户端pom.xml

    4.0.0

    cn.edu.tju
    nettyechoclient
    1.0-SNAPSHOT
    
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    8
                    8
                
            

        
    
    
        
        
            io.netty
            netty-all
            4.0.0.Final
        

        
        
            com.google.protobuf
            protobuf-java
            3.0.0
        




    

5.客户端ChannelHandler

package cn.edu.tju.handler;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import java.util.Date;

public class ClientChannelHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx,Object msg){
        String str=(String)msg;
        System.out.println(str);
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx){
        for(int i=0;i<10000;i++){
            String msg=new Date().toLocaleString()+"rn";
            ByteBuf message=null;
            message= Unpooled.buffer(msg.length());
            message.writeBytes(msg.getBytes());
            ctx.writeAndFlush(message);
        }

    }

    @Override
    public  void exceptionCaught(ChannelHandlerContext ctx,Throwable cause){
        System.out.println(cause.getMessage());
    }
}

6.客户端主类：

package cn.edu.tju;

import cn.edu.tju.handler.ClientChannelHandler;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
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;

public class Start {
    private static int port=8899;
    private static String host="127.0.0.1";
    public static void main(String[] args) {
        NioEventLoopGroup group=new NioEventLoopGroup();
        try{
            Bootstrap bootstrap=new Bootstrap();
            bootstrap.group(group).channel(NioSocketChannel.class).handler(new ChannelInitializer() {

                @Override
                protected void initChannel(SocketChannel ch) throws Exception {
                    //以下3个ChannelHandler顺序不能改变
                    ch.pipeline().addLast(new LinebasedframeDecoder(1024));
                    ch.pipeline().addLast(new StringDecoder());
                    ch.pipeline().addLast(new ClientChannelHandler());
                }
            });
            ChannelFuture f=bootstrap.connect(host,port).sync();
            f.channel().closeFuture().sync();
        }catch (Exception ex){
            System.out.println(ex.getMessage());
        }finally {
            group.shutdownGracefully();
        }

    }
}

7.运行服务器端和客户端，可以看到服务器端收到的消息并未发生粘包