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Netty聊天室

项目结构

服务端

Server

public class GroupChatServer {
       private int port; //监听端口    public GroupChatServer(int port) {
           this.port = port;    }    //编写run方法，处理客户端请求    public void run() throws InterruptedException {
           //创建两个线程组        EventLoopGroup bossGroup = new NioEventLoopGroup(1);        EventLoopGroup workerGroup = new NioEventLoopGroup();        try {
               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pipeline                            ChannelPipeline pipeline = ch.pipeline();                            //pipeline加入解码器                            pipeline.addLast("decoder",new StringDecoder());                            //pipeline加入编码器                            pipeline.addLast("encoder",new StringEncoder());                            //加入组件的业务处理的handler                            pipeline.addLast(new GroupChatServerHandler());                        }                    });            System.out.println("netty 服务器启动");            ChannelFuture channelFuture = serverBootstrap.bind(port).sync();            //监听关闭            channelFuture.channel().closeFuture().sync();        }finally {
               bossGroup.shutdownGracefully();            workerGroup.shutdownGracefully();        }    }    public static void main(String[] args) throws InterruptedException {
           new GroupChatServer(6666).run();    }}
   

ServerHandler

public class GroupChatServerHandler extends SimpleChannelInboundHandler
   
     {
       //定义一个channle组，管理所有的channel    //GlobalEventExecutor.INSTANCE 是全局事件执行器，是一个单例    private static ChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);    //一但建立连接，该方法就会被执行    @Override    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
           Channel channel = ctx.channel();        //将该客户加入聊天的信息推送给其它在线的客户端        //该方法会把channelGroup的所有channel遍历，调用writeAndFlush方法        channelGroup.writeAndFlush("[客户端]"+channel.remoteAddress()+"加入聊天\n");        channelGroup.add(channel);    }    //一但断开连接，该方法就会被执行    @Override    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
           //提示其它所有用户当前用户已经离线        Channel channel = ctx.channel();        channelGroup.writeAndFlush("[客户端]"+channel.remoteAddress()+"离开了\n");        System.out.println("channelGroup size"+channelGroup.size());    }    //channel 处于活动状态执行该方法    @Override    public void channelActive(ChannelHandlerContext ctx) throws Exception {
           System.out.println(ctx.channel().remoteAddress()+"上线了~");    }    //channel 处于非活动状态执行该方法    @Override    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
           System.out.println(ctx.channel().remoteAddress()+"离线了~");    }    //读取数据时触发    @Override    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
           Channel channel = ctx.channel();        //遍历channelGroup根据不同情况，回送不同消息        channelGroup.forEach(ch -> {
               if (channel != ch){
    //不是读取的channel，转发                ch.writeAndFlush("[用户]"+channel.remoteAddress() +" 发送了消息: "+msg+"\n");            }else {
                   ch.writeAndFlush("[自己]发送了消息: "+msg+"\n");            }        });    }    //发生异常触发    @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
           //关闭通道        ctx.close();    }}
   

客户端

Client

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 InterruptedException {
           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 {
                               //得到pipeline                            ChannelPipeline pipeline = ch.pipeline();                            //pipeline加入解码器                            pipeline.addLast("decoder",new StringDecoder());                            //pipeline加入编码器                            pipeline.addLast("encoder",new StringEncoder());                            //加入自定义handler                            pipeline.addLast(new GroupChatClientHandler());                        }                    });            ChannelFuture channelFuture = bootstrap.connect(host, port).sync();            Channel channel = channelFuture.channel();            System.out.println("----------"+channel.localAddress()+"----------");            //客户端需要输入消息            Scanner scanner = new Scanner(System.in);            while (scanner.hasNextLine()){
                   String msg = scanner.nextLine();                //通过channel 发生到服务器端                channel.writeAndFlush(msg+"\r\n");            }        }finally {
               group.shutdownGracefully();        }    }    public static void main(String[] args) throws InterruptedException {
           new GroupChatClient("localhost",6666).run();    }}
   

ClientHandler

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

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