基于netty的websocket例子

nettyServer

package com.atguigu.netty.websocket;
import javax.annotation.PostConstruct;
import org.springframework.stereotype.Service;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.stream.ChunkedWriteHandler;
/**
* ClassName:NettyServer 注解式随spring启动
* Function: TODO ADD FUNCTION.
* @author fwz
*/
@Service
public class NettyServer {
public static void main(String[] args) {
new NettyServer().run();
}
@PostConstruct
public void initNetty(){
new Thread(){
public void run() {
new NettyServer().run();
}
}.start();
}
public void run(){
System.out.println("===========================Netty端口启动========");
// Boss线程：由这个线程池提供的线程是boss种类的，用于创建、连接、绑定socket， （有点像门卫）然后把这些socket传给worker线程池。
// 在服务器端每个监听的socket都有一个boss线程来处理。在客户端，只有一个boss线程来处理所有的socket。
EventLoopGroup bossGroup = new NioEventLoopGroup();
// Worker线程：Worker线程执行所有的异步I/O，即处理操作
EventLoopGroup workGroup = new NioEventLoopGroup();
try {
// ServerBootstrap 启动NIO服务的辅助启动类,负责初始话netty服务器，并且开始监听端口的socket请求
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workGroup);
// 设置非阻塞,用它来建立新accept的连接,用于构造serversocketchannel的工厂类
b.channel(NioServerSocketChannel.class);
// ChildChannelHandler 对出入的数据进行的业务操作,其继承ChannelInitializer
b.childHandler(new ChildChannelHandler());
System.out.println("服务端开启等待客户端连接 ... ...");
Channel ch = b.bind().sync().channel();
ch.closeFuture().sync();
} catch (Exception e) {
e.printStackTrace();
}finally{
bossGroup.shutdownGracefully();
workGroup.shutdownGracefully();
}
}

private class ChildChannelHandler extends ChannelInitializer<SocketChannel>{
@Override
protected void initChannel(SocketChannel e) throws Exception {
// 设置30秒没有读到数据，则触发一个READER_IDLE事件。
// pipeline.addLast(new IdleStateHandler(30, 0, 0));
// HttpServerCodec：将请求和应答消息解码为HTTP消息
e.pipeline().addLast("http-codec",new HttpServerCodec());
// HttpObjectAggregator：将HTTP消息的多个部分合成一条完整的HTTP消息
e.pipeline().addLast("aggregator",new HttpObjectAggregator());
// ChunkedWriteHandler：向客户端发送HTML5文件
e.pipeline().addLast("http-chunked",new ChunkedWriteHandler());
// 在管道中添加我们自己的接收数据实现方法
e.pipeline().addLast("handler",new MyWebSocketServerHandler());
}
}

}

MyWebSocketServerHandler

package com.atguigu.netty.websocket;

import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
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.HttpHeaderNames;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpUtil;
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.AttributeKey;
import io.netty.util.CharsetUtil;

/**
 * ClassName:MyWebSocketServerHandler Function: TODO ADD FUNCTION.
 *
 * @author fwz
 */
public class MyWebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
    private static final Logger logger = Logger.getLogger(WebSocketServerHandshaker.class.getName());
    private WebSocketServerHandshaker handshaker;

    /**
     * channel 通道 action 活跃的 当客户端主动链接服务端的链接后，这个通道就是活跃的了。也就是客户端与服务端建立了通信通道并且可以传输数据
     */
    @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：" + ctx.channel().remoteAddress().toString());
    }

    /**
     * channel 通道 Inactive 不活跃的
     * 当客户端主动断开服务端的链接后，这个通道就是不活跃的。也就是说客户端与服务端关闭了通信通道并且不可以传输数据
     */
    @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：" + ctx.channel().remoteAddress().toString());
    }

    /**
     * 接收客户端发送的消息 channel 通道 Read 读
     * 简而言之就是从通道中读取数据，也就是服务端接收客户端发来的数据。但是这个数据在不进行解码时它是ByteBuf类型的
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
// 传统的HTTP接入
        if (msg instanceof FullHttpRequest) {
            handleHttpRequest(ctx, ((FullHttpRequest) msg));
// WebSocket接入
        } else if (msg instanceof WebSocketFrame) {
            System.out.println(handshaker.uri());
            if ("anzhuo".equals(ctx.channel().attr(AttributeKey.valueOf("type")).get())) {
                handlerWebSocketFrame(ctx, (WebSocketFrame) msg);
            } else {
                handlerWebSocketFrame2(ctx, (WebSocketFrame) msg);
            }
        }
    }

    /**
     * channel 通道 Read 读取 Complete 完成 在通道读取完成后会在这个方法里通知，对应可以做刷新操作 ctx.flush()
     */
    @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) {
            System.out.println();
            handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
            return;
        }
// 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 handlerWebSocketFrame2(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());
            return;
        }
// 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2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) {
// 如果HTTP解码失败，返回HHTP异常
        if (!req.decoderResult().isSuccess() || (!"websocket".equals(req.headers().get("Upgrade")))) {
            sendHttpResponse(ctx, req,
                    new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST));
            return;
        }
//获取url后置参数
        String uri = req.uri();

// 构造握手响应返回，本机测试
        WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
                "ws://localhost:8081/websocket" , null, false);
        handshaker = wsFactory.newHandshaker(req);
        if (handshaker == null) {
            WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(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.status().code() != ) {
            ByteBuf buf = Unpooled.copiedBuffer(res.status().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 (!HttpUtil.isKeepAlive(req) || res.status().code() != ) {
            f.addListener(ChannelFutureListener.CLOSE);
        }
    }

    /**
     * exception 异常 Caught 抓住 抓住异常，当发生异常的时候，可以做一些相应的处理，比如打印日志、关闭链接
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
        // TODO Auto-generated method stub

    }
}

Global

package com.atguigu.netty.websocket;

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

/**
* ClassName:Global
* Function: TODO ADD FUNCTION.
* @author fwz
*/
public class Global {
public static ChannelGroup group = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
}

controller

package com.atguigu.netty.websocket;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class DeptController_Consumer
{

    @RequestMapping(value = "/socketHtml")
    public String html()
    {
        return"WebSocketServer";
    }

}

WebSocketServer

<html>
<head>
<meta charset="UTF-8">
Netty WebSocket 时间服务器
</head>
<br>
<body>
<br>
    <script type="text/javascript">
        var socket;
        if (!window.WebSocket) {
            window.WebSocket = window.MozWebSocket;
        }
        if (window.WebSocket) {
            socket = new WebSocket(
                    "ws://localhost:8081/websocket");
            socket.onmessage = function(event) {
                var ta = document.getElementById("responseText");
                ta.value="";
                ta.value=event.data;
            };
            socket.onopen = function(event) {

                var ta = document.getElementById("responseText");
                ta.value="";
                ta.value="打开WebSocket服务正常，浏览器支持WebSocket！";
            };
            socket.onclose = function(event) {

                var ta = document.getElementById("responseText");
                ta.value="";
                ta.value="WebSocket关闭！";
            };
        }else{
            alert("抱歉，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("The socket is not open.");
            }
        }
    </script>
    <form onsubmit="return false;">
        <input type="text" name="message" value="Hello,Netty-WebSocket" />
        <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 style="width: 500px;height: 300px;" id="responseText" ></textarea>
    </form>
</body>
</html>

启动后如下：