基于Netty的简单群聊系统

╰+攻爆jí腚メ 2022-09-06 01:25 176阅读 0赞

客户端上下线信息被服务器端转发给其他客户端；

客户端发送的信息被服务器端转发给其他客户端；

服务端：

package com.tech.netty.netty.groupchat;
    
    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;
    
    /**
     * @author lw
     * @since 2021/8/19
     */
    public class GroupChatServer {
    
        //监听端口
        private int port;
    
        public GroupChatServer(int port) {
            this.port = port;
        }
    
        public void run() throws InterruptedException {
    
            //创建两个线程组
            NioEventLoopGroup bossGroup = new NioEventLoopGroup();
            NioEventLoopGroup workerGroup = new NioEventLoopGroup();
    
            try {
                ServerBootstrap serverBootstrap = new ServerBootstrap();
    
                serverBootstrap.group(bossGroup, workerGroup)
                        .channel(NioServerSocketChannel.class)
                        .option(ChannelOption.SO_BACKLOG, 128) //服务端通道连接队列长度
                        .childOption(ChannelOption.SO_KEEPALIVE, true) //客户端通道保持活动状态
                        .childHandler(new ChannelInitializer<SocketChannel>() { //设置客户端通道绑定管道的处理器
                            @Override
                            protected void initChannel(SocketChannel socketChannel) throws Exception {
                                //获取管道
                                ChannelPipeline pipeline = socketChannel.pipeline();
                                pipeline.addLast("StringDecoder", new StringDecoder()) //向管道加入解码器
                                        .addLast("StringEncoder", new StringEncoder()) //向管道加入编码器
                                        .addLast(new GroupChatServerHandler()); //向管道加入自定义处理器
                            }
                        });
                //绑定端口启动服务器（同步运行）
                System.out.println("netty 服务器启动");
                ChannelFuture channelFuture = serverBootstrap.bind(port).sync();
                //向异步执行结果添加监听器监听关闭事件（同步运行）
                channelFuture.channel().closeFuture().sync();
            } finally {
                bossGroup.shutdownGracefully();
                workerGroup.shutdownGracefully();
            }
        }
    
        public static void main(String[] args) throws InterruptedException {
            new GroupChatServer(7000).run();
        }
    }

package com.tech.netty.netty.groupchat;
    
    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;
    import java.util.Date;
    
    /**
     * @author lw
     * @since 2021/8/19
     */
    public class GroupChatServerHandler extends SimpleChannelInboundHandler<String> {
    
        //定义一个通道组，管理所有通道（通道需要手动加入，在特定事件下自动移除）
        //GlobalEventExecutor.INSTANCE 单例的全局事件执行器
        private static ChannelGroup channelGroup=new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
    
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    
        //新的客户端连接事件 有新的客户端连接第一个触发
        @Override
        public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
            Channel channel = ctx.channel();
            //将客户端加入的信息推送给其他客户端
            //channelGroup 会给通道组中所有通道发送消息
            channelGroup.writeAndFlush("[客户端]"+channel.remoteAddress()+" 加入聊天 "+sdf.format(new Date())+"\n");
            channelGroup.add(channel);
        }
    
        //断开连接 将某某客户端下线的消息发送给其他客户端
        @Override
        public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
            Channel channel = ctx.channel();
            channelGroup.writeAndFlush("[客户端]"+channel.remoteAddress()+" 下线了 "+sdf.format(new Date())+"\n");
            System.out.println("channelGroupSize="+channelGroup.size());
        }
    
        //通道处于活动状态，提示客户端上线了
        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            Channel channel = ctx.channel();
            System.out.println(channel.remoteAddress()+" 上线了 "+sdf.format(new Date()));
        }
    
        //通道处于非活动状态，提示客户端下线了
        @Override
        public void channelInactive(ChannelHandlerContext ctx) throws Exception {
            Channel channel = ctx.channel();
            System.out.println(channel.remoteAddress()+"下线了 "+sdf.format(new Date()));
        }
    
        //读取数据
        @Override
        protected void channelRead0(ChannelHandlerContext ctx, String s) throws Exception {
            //获取当前通道
            Channel channel = ctx.channel();
            //遍历channelGroup 根据不同的情况，回送不同的信息
            channelGroup.forEach(c->{
                if(channel!=c){ //不是当前通道转发消息
                    c.writeAndFlush("[客户端]"+channel.remoteAddress()+" 发送了消息 "+s+" "+sdf.format(new Date())+"\n");
                }else{ //回显自己发送的消息给自己
                    channel.writeAndFlush("[自己]发送了消息"+s+" "+sdf.format(new Date())+"\n");
                }
            });
    
        }
    
        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
           //关闭通道
            ctx.close();
        }
    }

客户端：

package com.tech.netty.netty.groupchat;
    
    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;
    
    /**
     * @author lw
     * @since 2021/8/19
     */
    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 eventExecutors = new NioEventLoopGroup();
            try{
                Bootstrap bootstrap = new Bootstrap();
                bootstrap.group(eventExecutors)
                        .channel(NioSocketChannel.class)
                        .handler(new ChannelInitializer<SocketChannel>() {
                            @Override
                            protected void initChannel(SocketChannel socketChannel) throws Exception {
                                ChannelPipeline pipeline = socketChannel.pipeline();
                                pipeline.addLast("StringDecoder",new StringDecoder())
                                        .addLast("StringEncoder",new StringEncoder())
                                        .addLast(new GroupChatClientHandler());
                            }
                        });
                ChannelFuture channelFuture = bootstrap.connect(host, port).sync();
                Channel channel = channelFuture.channel();
                System.out.println("----------------"+channel.localAddress()+"--------------------");
    
                //客户端需要输入信息 创建一个扫描器
                Scanner scanner = new Scanner(System.in);
                while(scanner.hasNextLine()){
                    String msg = scanner.nextLine();
                    //发送到服务器
                    channel.writeAndFlush(msg+"\r\n");
                }
            }finally {
                eventExecutors.shutdownGracefully();
            }
        }
    
        public static void main(String[] args) throws InterruptedException {
            new GroupChatClient("127.0.0.1",7000).run();
        }
    }

package com.tech.netty.netty.groupchat;
    
    import io.netty.channel.ChannelHandlerContext;
    import io.netty.channel.SimpleChannelInboundHandler;
    
    /**
     * @author lw
     * @since 2021/8/19
     */
    public class GroupChatClientHandler extends SimpleChannelInboundHandler<String> {
    
        @Override
        protected void channelRead0(ChannelHandlerContext channelHandlerContext, String s) throws Exception {
            System.out.println(s.trim());
        }
    }