5.使用Netty完成WebSocket

作者: 未知的证明 | 来源:发表于2019-02-22 15:11 被阅读0次

5.使用Netty完成WebSocket
Netty Websocket服务端心跳检测小计
netty中websocket
netty中websocket, wss
writeAndFlush乱序问题
WebSocket 协议 5~10 节
游戏架构
Netty + websocket聊天室
OkHttp使用分析—WebSocket篇
用SpringBoot集成Netty开发一个基于WebSocke

运行后主要截图如下：

网页截图

控制台输出

1.网页端代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>WebSocket客户端</title>
</head>
<body>
<script type="text/javascript">
    var socket;
    if(window.WebSocket) {
        socket = new WebSocket("ws://localhost:8899/ws");

        socket.onmessage = function(event) {
            var ta = document.getElementById("responseText");
            ta.value = ta.value + "\n" + event.data;
        }

        socket.onopen = function(event) {
            var ta = document.getElementById("responseText");
            ta.value = "连接开启！";
        }

        socket.onclose = function(event) {
            var ta = document.getElementById("responseText");
            ta.value = ta.value + "\n" + "连接关闭！";
        }
    } else {
        alert('浏览器不支持WebSocket!')
    }

    function send(message) {
        if(!window.WebSocket) {
            return;
        }

        if(socket.readyState == WebSocket.OPEN) {
            socket.send(message);
        } else {
            alert("连接尚未开启！");
        }
    }
</script>
<form onsubmit="return false;">
    <textarea name="message" style="width: 400px; height: 200px"></textarea>
    <input type="button" value="发送数据" onclick="send(this.form.message.value)">
    <h3>服务端输出：</h3>
    <textarea id="responseText" style="width: 400px; height: 300px;"></textarea>
    <input type="button" onclick="javascript: document.getElementById('responseText').value=''" value="清空内容">
</form>
</body>
</html>

2.Netty服务端主程序

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
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;
import java.net.InetSocketAddress;
public class MyServer {
    public static void main(String[] args) throws InterruptedException {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workGroup).channel(NioServerSocketChannel.class)
                    .handler(new LoggingHandler(LogLevel.INFO))
                    .childHandler(new WebSocketChannelInitializer());
            ChannelFuture channelFuture = serverBootstrap.bind(new InetSocketAddress(8899)).sync();
            channelFuture.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }

    }
}

3.Netty服务端的Initializer程序

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 ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast(new HttpServerCodec());
        pipeline.addLast(new ChunkedWriteHandler());
        pipeline.addLast(new HttpObjectAggregator(8192));
        pipeline.addLast(new WebSocketServerProtocolHandler("/ws"));
        pipeline.addLast(new TextWebSocketFrameHandler());
    }
}

4.Netty服务端Handler

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import java.time.LocalDateTime;
public class TextWebSocketFrameHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
        System.out.println("【收到消息】：" + msg.text());
        ctx.writeAndFlush(new TextWebSocketFrame("服务器时间：" + LocalDateTime.now()));
    }
    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        System.out.println("Handler Added:" + ctx.channel().id().asLongText());
    }
    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        System.out.println("Handler Removed:" + ctx.channel().id().asLongText());
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        System.out.println("异常发生");
        ctx.close();
    }
}