Netty+Websocket实现简单的回声聊天服务器

Netty Websocket 回声聊天室案例

讲解参照我netty聊天室的博客
Demo源码地址https://gitee.com/HumorChen/netty_websocket_demo 仅供参考

• 项目名

  netty_websocket_demo
  

• Maven依赖

  完整依赖在最后

  <!--netty的依赖集合，都整合在一个依赖里面了-->
  <dependency>
      <groupId>io.netty</groupId>
      <artifactId>netty-all</artifactId>
      <version>4.1.25.Final</version>
  </dependency>
  

• NettyWebServer类

  package com.example.netty_websocket_demo.server;
  
  import com.example.netty_websocket_demo.handler.NettyWebSocketHandler;
  import io.netty.bootstrap.ServerBootstrap;
  import io.netty.channel.*;
  import io.netty.channel.nio.NioEventLoopGroup;
  import io.netty.channel.socket.SocketChannel;
  import io.netty.channel.socket.nio.NioServerSocketChannel;
  import io.netty.handler.codec.http.HttpObjectAggregator;
  import io.netty.handler.codec.http.HttpServerCodec;
  import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
  import io.netty.handler.stream.ChunkedWriteHandler;
  
  public class NettyWebServer {
      public static void run (){
          //boss线程组用来接收连接
          EventLoopGroup boss=new NioEventLoopGroup();
          //worker线程组用来处理消息
          EventLoopGroup worker=new NioEventLoopGroup();
          try {
              //辅助启动工具类
              ServerBootstrap bootstrap=new ServerBootstrap();
              bootstrap.group(boss,worker).channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer<SocketChannel>() {
                  @Override
                  protected void initChannel(SocketChannel ch) throws Exception {
                      ChannelPipeline pipeline=ch.pipeline();
                      //http编码解码器
                      pipeline.addLast(new HttpServerCodec());
                      //分块传输
                      pipeline.addLast(new ChunkedWriteHandler());
                      //块聚合
                      pipeline.addLast(new HttpObjectAggregator(1024*1024));
                      //协议处理器
                      pipeline.addLast(new WebSocketServerProtocolHandler("/ws"));
                      //自定义的处理器
                      pipeline.addLast(new NettyWebSocketHandler());
                  }
              });
              //绑定端口，同步启动
              ChannelFuture future=bootstrap.bind(8081).sync();
              future.channel().closeFuture().sync();
          }catch (Exception e){
              e.printStackTrace();
          }finally {
              boss.shutdownGracefully();
              worker.shutdownGracefully();
          }
      }
  
      public static void main(String[] args) {
          run();
      }
  }
  
  

• NettyWebSocketHandler类

  package com.example.netty_websocket_demo.handler;
  
  import io.netty.channel.*;
  import io.netty.channel.group.ChannelGroup;
  import io.netty.channel.group.DefaultChannelGroup;
  import io.netty.handler.codec.http.websocketx.*;
  import io.netty.util.concurrent.GlobalEventExecutor;
  
  /**
   * NettyWebsocket文本消息处理器
   */
  public class NettyWebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
      // 用于记录和管理所有客户端的channle
      private static ChannelGroup clients = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
  
      @Override
      protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg)
              throws Exception {
          // 获取客户端传输过来的消息
          String content = msg.text();
          System.out.println("服务器接收到的数据：" + content);
          //群发给所有连接
  //    	for (Channel channel: clients) {
  //			channel.writeAndFlush(
  //				new TextWebSocketFrame(
  //						"[服务器在]" + LocalDateTime.now()
  //						+ "接受到消息, 消息为：" + content));
  //		}
          // 下面这个方法，和上面的for循环，一致   向客户端发送数据
          clients.writeAndFlush(new TextWebSocketFrame("我是服务器,我收到你的消息为:" + content));
      }
  
      /**
       * 当客户端连接服务端之后（打开连接）
       * 获取客户端的channle，并且放到ChannelGroup中去进行管理
       */
      @Override
      public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
          clients.add(ctx.channel());
      }
  
      @Override
      public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
          // 当触发handlerRemoved，ChannelGroup会自动移除对应客户端的channel,所以下面的remove不用我们再手写
          //		clients.remove(ctx.channel());
          System.out.println("客户端断开，channle对应的长id为：" + ctx.channel().id().asLongText());
          System.out.println("客户端断开，channle对应的短id为：" + ctx.channel().id().asShortText());
      }
  }
  
  
  

• 验证使用SpringBoot和一个html页面

• Application类

  package com.example.netty_websocket_demo;
  
  import com.example.netty_websocket_demo.server.NettyWebServer;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.boot.context.event.ApplicationReadyEvent;
  import org.springframework.context.ApplicationListener;
  
  @SpringBootApplication
  public class NettyWebsocketDemoApplication implements ApplicationListener<ApplicationReadyEvent> {
  
      public static void main(String[] args) {
          SpringApplication.run(NettyWebsocketDemoApplication.class, args);
      }
  
      @Override
      public void onApplicationEvent(ApplicationReadyEvent applicationReadyEvent) {
          //springboot启动完成后启动netty
          NettyWebServer.run();
      }
  }
  
  

• Html页面

  index.html (src\main\resources\static\index.html)
  

  <!DOCTYPE html>
  <html lang="en">
  <head>
      <meta charset="UTF-8">
      <title>WebSocketTest</title>
      <script>
          url='ws://localhost:8081/ws'
          if (!window.WebSocket) {
              window.WebSocket = window.MozWebSocket
          }
          if (window.WebSocket) {
              socket = new WebSocket(url)
              socket.onopen = function(event) {
                  addMsg('连接成功')
                  console.log(event)
              }
              socket.onclose = function(event) {
                  addMsg('连接被关闭')
              }
              socket.onmessage = function(event) {
                  addMsg("【服务器】："+event.data)
              }
          } else {
              alert('你的浏览器不支持 WebSocket！')
          }
  
          function addMsg(msg) {
              let content=document.getElementById('content')
              content.innerHTML=content.innerHTML+msg+"<br>"
          }
          function send() {
              let msg=document.getElementById('input').value
              if(msg){
                  if (!window.WebSocket) {
                      return
                  }
                  if (socket.readyState == WebSocket.OPEN) {
                      socket.send(msg)
                      addMsg("【客户端】："+msg)
                      document.getElementById('input').value=''
                  } else {
                      alert('连接没有开启.')
                  }
              }else{
                  alert('不允许空消息')
              }
          }
      </script>
  </head>
  <body>
  <div  id="content" style="width: 800px;height: 600px;">
  
  </div>
  <div style="width: 800px;height: 120px">
      <textarea  id="input" placeholder="请输入短信内容" style="width: 100%;height: 80px"></textarea>
      <button onclick="send()">发送</button>
  </div>
  </body>
  </html>
  

  - 启动 NettyWebsocketDemoApplication
  - 浏览器访问localhost即可测试