前面2文
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：
package com.bill.websocketdemo;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
public class WebSocketServer {
public static void main(String[] args) throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try{
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).
handler(new LoggingHandler(LogLevel.INFO)).childHandler(new WebSocketChannelInitializer());
ChannelFuture channelFuture = serverBootstrap.bind(8899).sync();
channelFuture.channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
package com.bill.websocketdemo;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
@Override
protected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {
System.out.println("收到消息：" + textWebSocketFrame.text());
channelHandlerContext.channel().writeAndFlush(new TextWebSocketFrame("服务器随机数：" + Math.random()));
}
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
System.out.println("handlerAdded!!!");
}
@Override
public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
System.out.println("handlerRemoved!!!");
}
}
package com.bill.websocketdemo;
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 socketChannel) throws Exception {
ChannelPipeline pipeline = socketChannel.pipeline();
pipeline.addLast(new HttpServerCodec());
pipeline.addLast(new ChunkedWriteHandler());
pipeline.addLast(new HttpObjectAggregator(8192));
pipeline.addLast(new WebSocketServerProtocolHandler("/hello"));
pipeline.addLast(new WebSocketHandler());
}
}
HTML代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>websocket</title>
</head>
<body>
<script type="text/javascript">
var socket;
if(window.WebSocket) {
socket = new WebSocket("ws://localhost:8899/hello");
socket.onmessage = function (event) {
var ta = document.getElementById("resp");
ta.value = ta.value + "\n" + event.data;
}
socket.onopen = function (event) {
var ta = document.getElementById("resp");
ta.value = "连接接开启！";
}
socket.onclose = function (event) {
var ta = document.getElementById("resp");
ta.value = ta.value + "\n" + "连接关闭！";
}
} else {
alert("浏览器不支持websocket");
}
function send(msg) {
if(!window.WebSocket) {
return;
}
if(socket.readyState == WebSocket.OPEN) {
socket.send(msg);
} else {
alert("连接未开启！")
}
}
</script>
<form onsubmit="return false;">
<textarea id="message" style="width: 400px; height: 200px"></textarea>
<input type="button" value="发送数据" onclick="send(this.form.message.value)">
<h3> 服务器输出：</h3>
<textarea id="resp" style="width: 400px; height: 300px"></textarea>
<input type="button" onclick="javascript: document.getElementById('resp').value = ''" value="清空内容">
</form>
</body>
</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：