Netty入门之WebSocket-2

课程代码
websocket.html

<html>
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset = utf-8"/>
		<title>WebSocket客户端</title>
	<script type="text/javascript">
		var socket;
		if(!window.WebSocket){
			window.WebSocket = window.MozWebSocket;
		}

		if(window.WebSocket){
			socket = new WebSocket("ws://localhost:8888/websocket");
			socket.onmessage = function(event){
				var ta = document.getElementById('responseContent');
				ta.value += event.data + "\r\n";
			};

			socket.onopen = function(event){
				var ta = document.getElementById('responseContent');
				ta.value = "你当前的浏览器支持WebSocket,请进行后续操作\r\n";
			};

			socket.onclose = function(event){
				var ta = document.getElementById('responseContent');
				ta.value = "";
				ta.value = "WebSocket连接已经关闭\r\n";
			};
		}else{
			alert("您的浏览器不支持WebSocket");
		}


		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>
	</head>
	<body>
		<form onSubmit="return false;">
			<input type = "text" name = "message" value = ""/>
			<br/><br/>
			<input type = "button" value = "发送WebSocket请求消息" onClick = "send(this.form.message.value)"/>
			<hr color="red"/>
			<h2>客户端接收到服务端返回的应答消息</h2>
			<textarea id = "responseContent" style = "width:1024px; height:300px"></textarea>
		</form>
	</body>
</html>

NettyConfig.java

package com.imooc.netty;

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

/**
 * 存储整个工程的全局配置
 * @author liuyazhuang
 *
 */
public class NettyConfig {
	
	/**
	 * 存储每一个客户端接入进来时的channel对象
	 */
	public static ChannelGroup group = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
}

MyWebSocketHandler.java

package com.imooc.netty;

import java.util.Date;

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.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;

/**
 * 接收/处理/响应客户端websocket请求的核心业务处理类
 * @author liuyazhuang
 *
 */
public class MyWebSocketHandler extends SimpleChannelInboundHandler<Object> {
	
	private WebSocketServerHandshaker handshaker;
	private static final String WEB_SOCKET_URL = "ws://localhost:8888/websocket";
	//客户端与服务端创建连接的时候调用
	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		NettyConfig.group.add(ctx.channel());
		System.out.println("客户端与服务端连接开启...");
	}

	//客户端与服务端断开连接的时候调用
	@Override
	public void channelInactive(ChannelHandlerContext ctx) throws Exception {
		NettyConfig.group.remove(ctx.channel());
		System.out.println("客户端与服务端连接关闭...");
	}

	//服务端接收客户端发送过来的数据结束之后调用
	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
			ctx.flush();
	}

	//工程出现异常的时候调用
	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
		cause.printStackTrace();
		ctx.close();
	}

	//服务端处理客户端websocket请求的核心方法
	@Override
	protected void messageReceived(ChannelHandlerContext context, Object msg) throws Exception {
		//处理客户端向服务端发起http握手请求的业务
		if (msg instanceof FullHttpRequest) {
			handHttpRequest(context,  (FullHttpRequest)msg);
		}else if (msg instanceof WebSocketFrame) { //处理websocket连接业务
			handWebsocketFrame(context, (WebSocketFrame)msg);
		}
	}
	
	/**
	 * 处理客户端与服务端之前的websocket业务
	 * @param ctx
	 * @param frame
	 */
	private void handWebsocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame){
		//判断是否是关闭websocket的指令
		if (frame instanceof CloseWebSocketFrame) {
			handshaker.close(ctx.channel(), (CloseWebSocketFrame)frame.retain());
		}
		//判断是否是ping消息
		if (frame instanceof PingWebSocketFrame) {
			ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
			return;
		}
		
		//判断是否是二进制消息，如果是二进制消息，抛出异常
		if( ! (frame instanceof TextWebSocketFrame) ){
			System.out.println("目前我们不支持二进制消息");
			throw new RuntimeException("【"+this.getClass().getName()+"】不支持消息");
		}
		//返回应答消息
		//获取客户端向服务端发送的消息
		String request = ((TextWebSocketFrame) frame).text();
		System.out.println("服务端收到客户端的消息====>>>" + request);
		TextWebSocketFrame tws = new TextWebSocketFrame(new Date().toString() 
																								+ ctx.channel().id() 
																								+ " ===>>> " 
																								+ request);
		//群发，服务端向每个连接上来的客户端群发消息
		NettyConfig.group.writeAndFlush(tws);
	}
	/**
	 * 处理客户端向服务端发起http握手请求的业务
	 * @param ctx
	 * @param req
	 */
	private void handHttpRequest(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(
				WEB_SOCKET_URL, null, false);
		handshaker = wsFactory.newHandshaker(req);
		if (handshaker == null) {
			WebSocketServerHandshakerFactory.sendUnsupportedWebSocketVersionResponse(ctx.channel());
		}else{
			handshaker.handshake(ctx.channel(), req);
		}
	}
	
	/**
	 * 服务端向客户端响应消息
	 * @param ctx
	 * @param req
	 * @param res
	 */
	private void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req,
			DefaultFullHttpResponse res){
		if (res.getStatus().code() != 200) {
			ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
			res.content().writeBytes(buf);
			buf.release();
		}
		//服务端向客户端发送数据
		ChannelFuture f = ctx.channel().writeAndFlush(res);
		if (res.getStatus().code() != 200) {
			f.addListener(ChannelFutureListener.CLOSE);
		}
	}
}

MyWebSocketChannelHandler.java

package com.imooc.netty;

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;

/**
 * 初始化连接时候的各个组件
 * @author liuyazhuang
 *
 */
public class MyWebSocketChannelHandler 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 MyWebSocketHandler());
	}

}

Main.java

package com.imooc.netty;

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

/**
 * 程序的入口，负责启动应用
 * @author liuyazhuang
 *
 */
public class Main {
	public static void main(String[] args) {
		EventLoopGroup bossGroup = new NioEventLoopGroup();
		EventLoopGroup workGroup = new NioEventLoopGroup();
		try {
			ServerBootstrap b = new ServerBootstrap();
			b.group(bossGroup, workGroup);
			b.channel(NioServerSocketChannel.class);
			b.childHandler(new MyWebSocketChannelHandler());
			System.out.println("服务端开启等待客户端连接....");
			Channel ch = b.bind(8888).sync().channel();
			ch.closeFuture().sync();
			
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			//优雅的退出程序
			bossGroup.shutdownGracefully();
			workGroup.shutdownGracefully();
		}
	}
}

Java > Netty

#Java #Netty

Netty入门之WebSocket-2

http://yoursite.com/2016/06/17/Java/Netty/Netty入门之WebSocket-2/

作者

mohuani

发布于

2016年6月17日

许可协议

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