6、netty第五个例子，使用websocket来通讯

websocket中，可以支持双向的数据通信。其中所有的数据格式，都是以帧的形式来传递。

initializer

 import io.netty.channel.ChannelInitializer;

 import io.netty.channel.ChannelPipeline;

 import io.netty.channel.socket.SocketChannel;

 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 WebSocketChannelinitializer extends ChannelInitializer<SocketChannel> {

     @Override

     protected void initChannel(SocketChannel ch) throws Exception {

         ChannelPipeline pipeline = ch.pipeline();

         pipeline.addLast(new HttpServerCodec());

         pipeline.addLast(new ChunkedWriteHandler());//分块的方式

         pipeline.addLast(new HttpObjectAggregator(8192));//http聚合 将块聚合成完整的

         pipeline.addLast(new WebSocketServerProtocolHandler("/ws"));//专门的websocket处理器， ws是指访问的路径

         pipeline.addLast(new TextWebSocketFrameHandler());

     }

 }

handler

 import io.netty.channel.Channel;

 import io.netty.channel.ChannelHandlerContext;

 import io.netty.channel.SimpleChannelInboundHandler;

 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;

 import java.time.LocalDateTime;

 /**

   * @ClassName:      TextWebSocketFrameHandler  websocket 都是以帧的形式来传递的，这里用的是文本

   * @Description:     描述

   * @Author:

   * @CreateDate:     2019/9/1 17:08

   * @Version:        1.0

  */

 public class TextWebSocketFrameHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {

     @Override

     protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {

         System.out.println("收到消息： " + msg.text());

         Channel channel = ctx.channel();

         channel.writeAndFlush(new TextWebSocketFrame("服务器时间： " + LocalDateTime.now()));

     }

     @Override

     public void handlerAdded(ChannelHandlerContext ctx) throws Exception {

         System.out.println("handlerAdded: " + ctx.channel().id().asLongText());//每个channel都有全局的id  分为长和短的 长的，保证唯一 短的不一定唯一

     }

     @Override

     public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {

         System.out.println("handlerRemoved: " + ctx.channel().id().asLongText());

     }

     @Override

     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {

         System.out.println("异常发生");

         ctx.close();

     }

 }

页面例子：

 <!DOCTYPE html>

 <html lang="en">

 <head>

     <meta charset="UTF-8">

     <title>WebSocket客户端</title>

 </head>

 <body>

 <!--第五个例子用到-->

 <form onsubmit="return false;">

     <textarea name="message" style="width: 400px;height: 200px">

     </textarea>

     <input type="button" value="发送短信" onclick="send(this.form.message.value)">

     <h3>服务器端输出：</h3>

     <textarea id="responseText" style="width: 400px; height: 300px">

     </textarea>

     <input type="button" onclick="javascript: document.getElementById('responseText').value = ''" value="清空内容">

 </form>

 <script type="application/javascript">

     var socket;

     if(window.WebSocket) {

         socket = new WebSocket("ws://localhost:8899/ws");

         socket.onmessage = function (ev) {

             //客户端获取到服务器端的消息

             var ta = document.getElementById("responseText");

             ta.value = ta.value + "\n" + ev.data;

         }

         socket.onopen = function (ev) {

             var ta = document.getElementById("responseText");

             ta.value = "连接开启";

         }

         socket.onclose  = function (ev) {

             var ta = document.getElementById("responseText");

             ta.value = ta.value + "\n" + "连接关闭";

         }

     } else {

         alert("浏览器不支持WebSocket");

     }

     function  send(message) {

         if(!window.WebSocket) {

             return;

         }

         if(socket.readyState == WebSocket.OPEN) {

             socket.send(message);

         } else {

             alert("连接未开启");

         }

     }

 </script>

 </body>

 </html>

巴特西

6、netty第五个例子，使用websocket来通讯

initializer

handler

页面例子：

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