基于websocket的netty demo

前面2文

基于http的netty demo

基于socket的netty demo

讲了netty在http和socket的使用，下面讲讲netty如何使用websocket

websocket是html5提出来的一个东西，功能很强大，可以支持长连接，实现服务器向客户端的通信，这里不做过多的介绍，只说说netty如何使用websocket作为协议来通信

这里采用表单提交的时候，使用websocket的方式提交，具体请看代码：

ps：我这里的代码架构是这样的

服务器代码：

 1 package com.bill.websocketdemo;
 2 
 3 
 4 import io.netty.bootstrap.ServerBootstrap;
 5 import io.netty.channel.ChannelFuture;
 6 import io.netty.channel.EventLoopGroup;
 7 import io.netty.channel.nio.NioEventLoopGroup;
 8 import io.netty.channel.socket.nio.NioServerSocketChannel;
 9 import io.netty.handler.logging.LogLevel;
10 import io.netty.handler.logging.LoggingHandler;
11 
12 public class WebSocketServer {
13 
14     public static void main(String[] args) throws Exception {
15         EventLoopGroup bossGroup = new NioEventLoopGroup();
16         EventLoopGroup workerGroup = new NioEventLoopGroup();
17 
18         try{
19             ServerBootstrap serverBootstrap = new ServerBootstrap();
20             serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).
21                     handler(new LoggingHandler(LogLevel.INFO)).childHandler(new WebSocketChannelInitializer());
22 
23             ChannelFuture channelFuture = serverBootstrap.bind(8899).sync();
24             channelFuture.channel().closeFuture().sync();
25         } finally {
26             bossGroup.shutdownGracefully();
27             workerGroup.shutdownGracefully();
28         }
29     }
30 }
31 
32 package com.bill.websocketdemo;
33 
34 
35 import io.netty.channel.ChannelHandlerContext;
36 import io.netty.channel.SimpleChannelInboundHandler;
37 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
38 
39 public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
40 
41     @Override
42     protected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {
43         System.out.println("收到消息：" + textWebSocketFrame.text());
44         channelHandlerContext.channel().writeAndFlush(new TextWebSocketFrame("服务器随机数：" + Math.random()));
45     }
46 
47     @Override
48     public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
49         System.out.println("handlerAdded!!!");
50     }
51 
52     @Override
53     public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
54         System.out.println("handlerRemoved!!!");
55     }
56 }
57 
58 package com.bill.websocketdemo;
59 
60 
61 import io.netty.channel.ChannelInitializer;
62 import io.netty.channel.ChannelPipeline;
63 import io.netty.channel.socket.SocketChannel;
64 import io.netty.handler.codec.http.HttpObjectAggregator;
65 import io.netty.handler.codec.http.HttpServerCodec;
66 import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
67 import io.netty.handler.stream.ChunkedWriteHandler;
68 
69 public class WebSocketChannelInitializer extends ChannelInitializer<SocketChannel> {
70 
71     @Override
72     protected void initChannel(SocketChannel socketChannel) throws Exception {
73 
74         ChannelPipeline pipeline = socketChannel.pipeline();
75 
76         pipeline.addLast(new HttpServerCodec());
77         pipeline.addLast(new ChunkedWriteHandler());
78         pipeline.addLast(new HttpObjectAggregator(8192));
79         pipeline.addLast(new WebSocketServerProtocolHandler("/hello"));
80 
81         pipeline.addLast(new WebSocketHandler());
82 
83     }
84 }

HTML代码：

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>websocket</title>
 6 </head>
 7 <body>
 8 
 9 <script type="text/javascript">
10     var socket;
11     if(window.WebSocket) {
12         socket = new WebSocket("ws://localhost:8899/hello");
13         socket.onmessage = function (event) {
14             var ta = document.getElementById("resp");
15             ta.value = ta.value + "
" + event.data;
16         }
17         
18         socket.onopen = function (event) {
19             var ta = document.getElementById("resp");
20             ta.value = "连接接开启！";
21         }
22         
23         socket.onclose = function (event) {
24             var ta = document.getElementById("resp");
25             ta.value = ta.value + "
" + "连接关闭！";
26         }
27     } else {
28         alert("浏览器不支持websocket");
29     }
30 
31     function send(msg) {
32         if(!window.WebSocket) {
33             return;
34         }
35 
36         if(socket.readyState == WebSocket.OPEN) {
37             socket.send(msg);
38         } else {
39             alert("连接未开启！")
40         }
41     }
42 
43 </script>
44 
45 <form onsubmit="return false;">
46 
47     <textarea id="message" style=" 400px; height: 200px"></textarea>
48     <input type="button" value="发送数据" onclick="send(this.form.message.value)">
49 
50     <h3> 服务器输出：</h3>
51 
52     <textarea id="resp" style=" 400px; height: 300px"></textarea>
53     <input type="button" onclick="javascript: document.getElementById('resp').value = ''" value="清空内容">
54 </form>
55 
56 
57 </body>
58 </html>

请注意：

运行的时候，先执行WebSocketServer的main方法，然后再run src/main/webapp/test.html ，这样 idea会自动启动一个页面

启动完服务器后，会在浏览器上看到页面：

服务器出现信息：

发送数据：

服务器：

完整代码下载：

https://download.csdn.net/download/mweibiao/10551574