基于Netty5.0高级案例一之NettyWebsocket

基于Netty5.0高级案例一之NettyWebsocket

2015-1-1 付政委 Netty5.0
高级篇

前言介绍：

本案例主要介绍如何使用Netty开发websocket。

环境需求：

1、jdk1.7

2、Eclipse

3、Netty5.0

4、支持websocket的浏览器[火狐]

工程截图：

代码部分：

服务端：



Global.java

package com.itstack.netty.common;

import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.util.concurrent.GlobalEventExecutor;

public class Global {

	public static ChannelGroup group = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

} 

ChildChannelHandler.java

package com.itstack.netty.websocket;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.stream.ChunkedWriteHandler;

public class ChildChannelHandler extends ChannelInitializer<SocketChannel>{

	@Override
	protected void initChannel(SocketChannel e) throws Exception {

		e.pipeline().addLast("http-codec",new HttpServerCodec());
		e.pipeline().addLast("aggregator",new HttpObjectAggregator(65536));
		e.pipeline().addLast("http-chunked",new ChunkedWriteHandler());
		e.pipeline().addLast("handler",new MyWebSocketServerHandler());
	}

} 

MyWebSocketServerHandler.java

package com.itstack.netty.websocket;

import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.itstack.netty.common.Global;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpRequest;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
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.util.CharsetUtil;

public class MyWebSocketServerHandler extends
		SimpleChannelInboundHandler<Object> {

	private static final Logger logger = Logger
			.getLogger(WebSocketServerHandshaker.class.getName());

	private WebSocketServerHandshaker handshaker;

	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {

		// 添加
		Global.group.add(ctx.channel());

		System.out.println("客户端与服务端连接开启");

	}

	@Override
	public void channelInactive(ChannelHandlerContext ctx) throws Exception {

		// 移除
		Global.group.remove(ctx.channel());

		System.out.println("客户端与服务端连接关闭");

	}

	@Override
	protected void messageReceived(ChannelHandlerContext ctx, Object msg)
			throws Exception {

		if (msg instanceof FullHttpRequest) {

			handleHttpRequest(ctx, ((FullHttpRequest) msg));

		} else if (msg instanceof WebSocketFrame) {

			handlerWebSocketFrame(ctx, (WebSocketFrame) msg);

		}

	}

	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
		ctx.flush();
	}

	private void handlerWebSocketFrame(ChannelHandlerContext ctx,
			WebSocketFrame frame) {

		// 判断是否关闭链路的指令
		if (frame instanceof CloseWebSocketFrame) {
			handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame
					.retain());
		}

		// 判断是否ping消息
		if (frame instanceof PingWebSocketFrame) {
			ctx.channel().write(
					new PongWebSocketFrame(frame.content().retain()));
			return;
		}

		// 本例程仅支持文本消息，不支持二进制消息
		if (!(frame instanceof TextWebSocketFrame)) {

			System.out.println("本例程仅支持文本消息，不支持二进制消息");

			throw new UnsupportedOperationException(String.format(
					"%s frame types not supported", frame.getClass().getName()));
		}

		// 返回应答消息
		String request = ((TextWebSocketFrame) frame).text();

		System.out.println("服务端收到：" + request);

		if (logger.isLoggable(Level.FINE)) {
			logger
					.fine(String.format("%s received %s", ctx.channel(),
							request));
		}

		TextWebSocketFrame tws = new TextWebSocketFrame(new Date().toString()
				+ ctx.channel().id() + "：" + request);

		// 群发
		Global.group.writeAndFlush(tws);

		// 返回【谁发的发给谁】
		// ctx.channel().writeAndFlush(tws);

	}

	private void handleHttpRequest(ChannelHandlerContext ctx,
			FullHttpRequest req) {

		if (!req.getDecoderResult().isSuccess()
				|| (!"websocket".equals(req.headers().get("Upgrade")))) {

			sendHttpResponse(ctx, req, new DefaultFullHttpResponse(
					HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST));

			return;
		}

		WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
				"ws://localhost:7397/websocket", null, false);

		handshaker = wsFactory.newHandshaker(req);

		if (handshaker == null) {
			WebSocketServerHandshakerFactory
					.sendUnsupportedWebSocketVersionResponse(ctx.channel());
		} else {
			handshaker.handshake(ctx.channel(), req);
		}

	}

	private static void sendHttpResponse(ChannelHandlerContext ctx,
			FullHttpRequest req, DefaultFullHttpResponse res) {

		// 返回应答给客户端
		if (res.getStatus().code() != 200) {
			ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(),
					CharsetUtil.UTF_8);
			res.content().writeBytes(buf);
			buf.release();
		}

		// 如果是非Keep-Alive，关闭连接
		ChannelFuture f = ctx.channel().writeAndFlush(res);
		if (!isKeepAlive(req) || res.getStatus().code() != 200) {
			f.addListener(ChannelFutureListener.CLOSE);
		}
	}

	private static boolean isKeepAlive(FullHttpRequest req) {

		return false;
	}

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

		cause.printStackTrace();
		ctx.close();

	}

} 

NettyServer.java

package com.itstack.netty.websocket;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class NettyServer {

	public static void main(String[] args) {

		new NettyServer().run();
	}

	public void run(){

		EventLoopGroup bossGroup = new NioEventLoopGroup();
		EventLoopGroup workGroup = new NioEventLoopGroup();

		try {

			ServerBootstrap b = new ServerBootstrap();
			b.group(bossGroup, workGroup);
			b.channel(NioServerSocketChannel.class);
			b.childHandler(new ChildChannelHandler());

			System.out.println("服务端开启等待客户端连接 ... ...");

			Channel ch = b.bind(7397).sync().channel();

			ch.closeFuture().sync();

		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			bossGroup.shutdownGracefully();
			workGroup.shutdownGracefully();
		}

	}

} 

客户端：

<!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>无标题文档</title>
</head>
</head>
<script type="text/javascript">
var socket;

if(!window.WebSocket){

window.WebSocket = window.MozWebSocket;
}

if(window.WebSocket){
socket = new WebSocket("ws://localhost:7397/websocket");

socket.onmessage = function(event){

var ta = document.getElementById('responseText');
ta.value += event.data+"\r\n";
};

socket.onopen = function(event){

var ta = document.getElementById('responseText');
ta.value = "打开WebSoket 服务正常，浏览器支持WebSoket!"+"\r\n";

};

socket.onclose = function(event){

var ta = document.getElementById('responseText');
ta.value = "";
ta.value = "WebSocket 关闭"+"\r\n";
};
}else{
alert("您的浏览器不支持WebSocket协议！");
}

function send(message){
if(!window.WebSocket){return;}
if(socket.readyState == WebSocket.OPEN){
socket.send(message);
}else{
alert("WebSocket 连接没有建立成功！");
}

}

</script>
<body>
<form onSubmit="return false;">
<input type = "text" name="message" value="Netty The Sinper"/>
<br/><br/>
<input type="button" value="发送 WebSocket 请求消息" onClick="send(this.form.message.value)"/>
<hr color="blue"/>
<h3>服务端返回的应答消息</h3>
<textarea id="responseText" style="width: 1024px;height: 300px;"></textarea>
</form>
</body>
</html>

测试运行：

1、启动NettyServer

2、启动支持websocket的浏览器，打开index.html【开启2个以上】

3、服务端输出结果：

服务端开启等待客户端连接 ... ...

客户端与服务端连接开启

客户端与服务端连接开启

客户端与服务端连接关闭

客户端与服务端连接开启

服务端收到：Netty The Sinper

服务端收到：Netty The Sinper

服务端收到：www.itstack.org

服务端收到：www.itstack.org

服务端收到：您好，您也在学习Netty吗？

服务端收到：是的！一起学习吧！

服务端收到：嗯，到群里来吧5360392

服务端收到：好的，么么大

4、客户端输出截图：