Netty实现聊天通信（4.0）

以下是netty4.0的代码，如果是5.0的代码请参考 —>
Netty之——基于Netty5.0高级案例NettyWebsocket
http://blog.csdn.net/l1028386804/article/details/55026558
1、Java代码

package com.test.netty4;  import io.netty.channel.ChannelHandlerContext;  import io.netty.handler.codec.http.FullHttpRequest;  public interface IHttpService {      void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest request);  }  

package com.test.netty4;  import io.netty.channel.ChannelHandlerContext;  import io.netty.handler.codec.http.websocketx.WebSocketFrame;  public interface IWebSocketService {      void handleFrame(ChannelHandlerContext ctx, WebSocketFrame frame);  }  

package com.test.netty4;  import java.util.Map;import java.util.concurrent.ConcurrentHashMap;import io.netty.bootstrap.ServerBootstrap;import io.netty.channel.Channel;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelFutureListener;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelId;import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.EventLoopGroup;import io.netty.channel.group.ChannelGroup;import io.netty.channel.group.DefaultChannelGroup;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioServerSocketChannel;import io.netty.handler.codec.http.FullHttpRequest;import io.netty.handler.codec.http.HttpHeaderNames;import io.netty.handler.codec.http.HttpHeaders;import io.netty.handler.codec.http.HttpMethod;import io.netty.handler.codec.http.HttpObjectAggregator;import io.netty.handler.codec.http.HttpServerCodec;import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;import io.netty.handler.codec.http.websocketx.WebSocketFrame;import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;import io.netty.handler.stream.ChunkedWriteHandler;import io.netty.util.AttributeKey;import io.netty.util.concurrent.GlobalEventExecutor;  public class WebSocketServer implements IWebSocketService, IHttpService {      public static void main(String[] args) {          new WebSocketServer(9999).start();      }      // ----------------------------static fields -----------------------------      private static final String HN_HTTP_CODEC = "HN_HTTP_CODEC";      private static final String HN_HTTP_AGGREGATOR = "HN_HTTP_AGGREGATOR";      private static final String HN_HTTP_CHUNK = "HN_HTTP_CHUNK";      private static final String HN_SERVER = "HN_LOGIC";      // handshaker attachment key      private static final AttributeKey<WebSocketServerHandshaker> ATTR_HANDSHAKER = AttributeKey.newInstance("ATTR_KEY_CHANNELID");      private static final int MAX_CONTENT_LENGTH = 65536;      private static final String WEBSOCKET_UPGRADE = "websocket";      private static final String WEBSOCKET_CONNECTION = "Upgrade";      private static final String WEBSOCKET_URI_ROOT_PATTERN = "ws://%s:%d";      // ------------------------ member fields -----------------------      private String host; // 绑定的地址      private int port; // 绑定的端口      /**      * 保存所有WebSocket连接      */      private Map<ChannelId, Channel> channelMap = new ConcurrentHashMap<ChannelId, Channel>();      private ChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);    private final String WEBSOCKET_URI_ROOT;      public WebSocketServer(int port) {          this("localhost", port);      }      public WebSocketServer(String host, int port) {          this.host = host;          this.port = port;          WEBSOCKET_URI_ROOT = String.format(WEBSOCKET_URI_ROOT_PATTERN, host, port);      }      public void start() {          EventLoopGroup bossGroup = new NioEventLoopGroup();          EventLoopGroup workerGroup = new NioEventLoopGroup();          ServerBootstrap b = new ServerBootstrap();          b.group(bossGroup, workerGroup);          b.channel(NioServerSocketChannel.class);          b.childHandler(new ChannelInitializer<Channel>() {              @Override              protected void initChannel(Channel ch) throws Exception {                  ChannelPipeline pl = ch.pipeline();                  // 保存该Channel的引用                  channelGroup.add(ch);                channelMap.put(ch.id(), ch);                  System.out.println("new channel {}"+ ch);                  ch.closeFuture().addListener(new ChannelFutureListener() {                      public void operationComplete(ChannelFuture future) throws Exception {                          System.out.println("channel close {}"+ future.channel());                          // Channel 关闭后不再引用该Channel                          channelMap.remove(future.channel().id());                      }                  });                  pl.addLast(HN_HTTP_CODEC, new HttpServerCodec());                  pl.addLast(HN_HTTP_AGGREGATOR, new HttpObjectAggregator(MAX_CONTENT_LENGTH));                  pl.addLast(HN_HTTP_CHUNK, new ChunkedWriteHandler());                  pl.addLast(HN_SERVER, new WebSocketServerHandler(WebSocketServer.this, WebSocketServer.this));              }          });          try {              // 绑定端口              ChannelFuture future = b.bind(host, port).addListener(new ChannelFutureListener() {                  public void operationComplete(ChannelFuture future) throws Exception {                      if (future.isSuccess()) {                          System.out.println("websocket started.");                      }                  }              }).sync();              future.channel().closeFuture().addListener(new ChannelFutureListener() {                  public void operationComplete(ChannelFuture future) throws Exception {                      System.out.println("server channel {} closed."+future.channel());                  }              }).sync();          } catch (InterruptedException e) {              e.printStackTrace();            //            logger.error(e.toString());          } finally {              bossGroup.shutdownGracefully();              workerGroup.shutdownGracefully();          }          System.out.println("websocket server shutdown");      }      /*       * @see cc.lixiaohui.demo.netty4.websocket.IHttpService#handleHttpRequest(io.netty.handler.codec.http.FullHttpRequest)      */      public void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) {          if (isWebSocketUpgrade(req)) { // 该请求是不是websocket upgrade请求               System.out.println("upgrade to websocket protocol");              String subProtocols = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL);              WebSocketServerHandshakerFactory factory = new WebSocketServerHandshakerFactory(WEBSOCKET_URI_ROOT, subProtocols, false);              WebSocketServerHandshaker handshaker = factory.newHandshaker(req);              if (handshaker == null) {// 请求头不合法, 导致handshaker没创建成功                  WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());              } else {                  // 响应该请求                  handshaker.handshake(ctx.channel(), req);                  // 把handshaker 绑定给Channel, 以便后面关闭连接用                  ctx.channel().attr(ATTR_HANDSHAKER).set(handshaker);// attach handshaker to this channel              }              return;          }          // TODO 忽略普通http请求          System.out.println("ignoring normal http request");      }      /*      * @see      * cc.lixiaohui.demo.netty4.websocket.IWebSocketService#handleFrame(io.netty      * .channel.Channel, io.netty.handler.codec.http.websocketx.WebSocketFrame)      */      public void handleFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {          // text frame          if (frame instanceof TextWebSocketFrame) {              String text = ((TextWebSocketFrame) frame).text();  //            TextWebSocketFrame rspFrame = new TextWebSocketFrame(text);              System.out.println("recieve TextWebSocketFrame from channel {}"+ ctx.channel());              // 发给其他所有channel  //            for (Channel ch : channelMap.values()) {  //                if (ctx.channel().equals(ch)) {   //                    continue;   //                }  //                TextWebSocketFrame rspFrame = new TextWebSocketFrame(text);  //                ch.writeAndFlush(rspFrame);  //                System.out.println("write text[{}] to channel {}"+ text+ ch);  //            }              TextWebSocketFrame rspFrame = new TextWebSocketFrame(text);              channelGroup.writeAndFlush(rspFrame);            return;          }          // ping frame, 回复pong frame即可          if (frame instanceof PingWebSocketFrame) {              System.out.println("recieve PingWebSocketFrame from channel {}"+ ctx.channel());              ctx.channel().writeAndFlush(new PongWebSocketFrame(frame.content().retain()));              return;          }          if (frame instanceof PongWebSocketFrame) {              System.out.println("recieve PongWebSocketFrame from channel {}"+ ctx.channel());              return;          }          // close frame,           if (frame instanceof CloseWebSocketFrame) {              System.out.println("recieve CloseWebSocketFrame from channel {}"+ ctx.channel());              WebSocketServerHandshaker handshaker = ctx.channel().attr(ATTR_HANDSHAKER).get();              if (handshaker == null) {                  System.out.println("channel {} have no HandShaker"+ ctx.channel());                  return;              }              handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());              return;          }          // 剩下的是binary frame, 忽略          System.out.println("unhandle binary frame from channel {}"+ctx.channel());      }      //三者与：1.GET? 2.Upgrade头 包含websocket字符串?  3.Connection头 包含 Upgrade字符串?      private boolean isWebSocketUpgrade(FullHttpRequest req) {          HttpHeaders headers = req.headers();          return req.getMethod().equals(HttpMethod.GET)                   && headers.get(HttpHeaderNames.UPGRADE).contains(WEBSOCKET_UPGRADE)                  && headers.get(HttpHeaderNames.CONNECTION).contains(WEBSOCKET_CONNECTION);      }  }  

package com.test.netty4;  import io.netty.channel.ChannelHandlerContext;  import io.netty.channel.SimpleChannelInboundHandler;  import io.netty.handler.codec.http.FullHttpRequest;  import io.netty.handler.codec.http.websocketx.WebSocketFrame;  public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {      @SuppressWarnings("unused")      private IWebSocketService websocketService;      private IHttpService httpService;      public WebSocketServerHandler(IWebSocketService websocketService, IHttpService httpService) {          super();          this.websocketService = websocketService;          this.httpService = httpService;      }      /*      * @see      * io.netty.channel.SimpleChannelInboundHandler#channelRead0(io.netty.channel      * .ChannelHandlerContext, java.lang.Object)      */      @Override      protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {          if (msg instanceof FullHttpRequest) {              httpService.handleHttpRequest(ctx, (FullHttpRequest) msg);          } else if (msg instanceof WebSocketFrame) {              websocketService.handleFrame(ctx, (WebSocketFrame) msg);          }      }      /*       * @see io.netty.channel.ChannelInboundHandlerAdapter#channelReadComplete(io.netty.channel.ChannelHandlerContext)      */      @Override      public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {          ctx.flush();      }     @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {    }}  

2、html页面代码

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">      <html xmlns="http://www.w3.org/1999/xhtml">      <head>      <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />      <title></title>      </head>        </head>        <script type="text/javascript">        var socket;        if(!window.WebSocket){            window.WebSocket = window.MozWebSocket;        }        if(window.WebSocket){            socket = new WebSocket("ws://localhost:9999");            socket.onmessage = function(event){                             appendln("接收:" + event.data);            };            socket.onopen = function(event){                  appendln("WebSocket 连接已建立");            };            socket.onclose = function(event){                  appendln("WebSocket 连接已关闭");            };        }else{              alert("浏览器不支持WebSocket协议");        }        function send(message){          if(!window.WebSocket){return;}          if(socket.readyState == WebSocket.OPEN){              socket.send(message);              appendln("发送:" + message);          }else{              alert("WebSocket连接建立失败");          }        }        function appendln(text) {          var ta = document.getElementById('responseText');          ta.value += text + "\r\n";        }        function clear() {          var ta = document.getElementById('responseText');          ta.value = "";        }        </script>        <body>          <form onSubmit="return false;">              <input type = "text" name="message" value="你好啊"/>              <br/><br/>              <input type="button" value="发送 WebSocket 请求消息" onClick="send(this.form.message.value)"/>              <hr/>              <h3>服务端返回的应答消息</h3>              <textarea id="responseText" style="width: 800px;height: 300px;"></textarea>          </form>        </body>      </html>  

3、启动 WebSocketServer 的main方法，然后打开多个html页面，即可实现聊天互通。更
此处是基于netty-all-4.1.12.Final.jar实现的。更详细的介绍可自行网络搜索。