8、Netty应用实例-群聊系统

服务器：

package com.atguigu.bio.nio.group;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

public class GroupChatServer {
     private  int port;//监听端口

    public GroupChatServer(int port) {
        this.port = port;
    }
    //编写run（）方法处理客户端的请求

    public void run() throws  Exception{


            //创建两个线程组
            NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);
            NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            //编写服务器端启动配置对象
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG, 128)
                    .childOption(ChannelOption.SO_KEEPALIVE, true)
                    .childHandler(new ChannelInitializer() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            //获取管道ChannelPipeline
                            ChannelPipeline pipeline = ch.pipeline();
                            //向pipeline加入解码器
                            pipeline.addLast("decoder", new StringDecoder());
                            //向pipeline加入编码器
                            pipeline.addLast("encode", new StringEncoder());
                            pipeline.addLast(new  GroupChatServerHandler());
                        }
                    });
            //绑定端口
            ChannelFuture channelFuture = serverBootstrap.bind(port);
            System.out.println("netty 服务器启动");
            //异步处理服务器关闭
            channelFuture.channel().closeFuture().sync();


        }finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();

        }
    }

    public static void main(String[] args) throws Exception {

        new GroupChatServer(7000).run();
    }
}

package com.atguigu.bio.nio.group;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.util.concurrent.GlobalEventExecutor;

import java.text.SimpleDateFormat;

public class GroupChatServerHandler extends SimpleChannelInboundHandler {
    //定义一个channel组，管理所有的channel
    //GlobalEventExecutor.INSTANCE 是全局的事件执行器，是一个单例
    private  static ChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    //将客户加入聊天的信息推送到其他客户端
    
    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        channelGroup.writeAndFlush("[客户端]"+channel.remoteAddress()+"加入聊天"+sdf.format(new java.util.Date())+"n");
        channelGroup.add(channel);
    }
   //表示channel处于活跃状态，后台（服务器）提示xx上线了
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {

        System.out.println(ctx.channel().remoteAddress()+"上线了");
    }
    //表示channel处于不活跃状态，后台（服务器）提示xx下线了
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        System.out.println(ctx.channel().remoteAddress()+"下线了");
    }

    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        channelGroup.writeAndFlush("[客户端]"+channel.remoteAddress()+"离开了n");
        System.out.println("channelGroup size"+channelGroup.size());
    }

    //读取数据
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        //获取当前的channel
        Channel channel = ctx.channel();
        //这时我们遍历channelGroup，根据不同的情况，回复不同的消息
        channelGroup.forEach(ch ->{
            if (channel!=ch){//不是当前的channel，转发消息
                ch.writeAndFlush("[客户]"+channel.remoteAddress()+"发送了消息"+msg+"n");
            }else{
                ch.writeAndFlush("[自己]发送了消息"+msg+"n");
            }
        } );

    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //关闭
        ctx.close();
    }
}

客户端：

package com.atguigu.bio.nio.group;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

import java.util.Scanner;

public class GroupChatClient {

    private final String host;
    private final int port;

    public GroupChatClient(String host, int port) {
        this.host = host;
        this.port = port;
    }

    public void run() throws Exception {
        NioEventLoopGroup group = new NioEventLoopGroup();
        try {

            Bootstrap bootstrap = new Bootstrap().group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            //获取管道ChannelPipeline
                            ChannelPipeline pipeline = ch.pipeline();
                            //向pipeline加入解码器
                            pipeline.addLast("decoder", new StringDecoder());
                            //向pipeline加入编码器
                            pipeline.addLast("encode", new StringEncoder());
                            pipeline.addLast(new GroupChatClientHandler());
                        }
                    });

            ChannelFuture channelFuture = bootstrap.connect(host,port).sync();
            //得到channel
            Channel channel = channelFuture.channel();
            System.out.println("------"+channel.localAddress()+"------");
            Scanner scanner = new Scanner(System.in);
            while (scanner.hasNextLine()){
                String msg = scanner.nextLine();
                channel.writeAndFlush(msg+"n");`在这里插入代码片`
            }
        } finally {
             group.shutdownGracefully();
        }

    }

    public static void main(String[] args) throws  Exception {
      new  GroupChatClient("127.0.0.1", 7000).run();
    }
}

package com.atguigu.bio.nio.group;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

public class GroupChatClientHandler extends SimpleChannelInboundHandler {
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        System.out.println(msg.trim());
    }
}