乐趣区

关于netty:Netty入门-基于netty的websocket聊天室

我的项目构造

服务端

public class MyServer {public static void main(String[] args) throws Exception{
 // 负责连贯的 NioEventLoopGroup 线程数为 1
 EventLoopGroup bossGroup = new NioEventLoopGroup(1);
 EventLoopGroup wokerGroup = new NioEventLoopGroup();
​
 try{ServerBootstrap serverBootstrap = new ServerBootstrap();
 serverBootstrap.group(bossGroup,wokerGroup).channel(NioServerSocketChannel.class)
 // 退出日志
 .handler(new LoggingHandler(LogLevel.INFO))
 // 自定义 channel 初始化器
 .childHandler(new WebSocketChannelInitializer());
 // 绑定本机的 8005 端口
 ChannelFuture channelFuture = serverBootstrap.bind(new InetSocketAddress(8005)).sync();
 // 异步回调 - 敞开事件
 channelFuture.channel().closeFuture().sync();}finally {bossGroup.shutdownGracefully();
 wokerGroup.shutdownGracefully();}
​
 }

channel 初始化器

public class WebSocketChannelInitializer extends ChannelInitializer<SocketChannel> {
 @Override
 protected void initChannel(SocketChannel ch) throws Exception {ChannelPipeline pipeline = ch.pipeline();
 //websocket 协定自身是基于 http 协定的,所以这边也要应用 http 解编码器
 pipeline.addLast(new HttpServerCodec());
 // 以块的形式来写的处理器
 pipeline.addLast(new ChunkedWriteHandler());
 //netty 是基于分段申请的,HttpObjectAggregator 的作用是将申请分段再聚合, 参数是聚合字节的最大长度
 pipeline.addLast(new HttpObjectAggregator(8192));
​
 // 应用 websocket 协定
 //ws://server:port/context_path
 // 参数指的是 contex_path
 pipeline.addLast(new WebSocketServerProtocolHandler("/world"));
 //websocket 定义了传递数据的中 frame 类型
 pipeline.addLast(new TextWebSocketFrameHandler());
 }
}

WebSocketChannelInitializerchannel 初始化器

public class WebSocketChannelInitializer extends ChannelInitializer<SocketChannel> {
 @Override
 protected void initChannel(SocketChannel ch) throws Exception {ChannelPipeline pipeline = ch.pipeline();
 //websocket 协定自身是基于 http 协定的,所以这边也要应用 http 解编码器
 pipeline.addLast(new HttpServerCodec());
 // 以块的形式来写的处理器
 pipeline.addLast(new ChunkedWriteHandler());
 //netty 是基于分段申请的,HttpObjectAggregator 的作用是将申请分段再聚合, 参数是聚合字节的最大长度
 pipeline.addLast(new HttpObjectAggregator(8192));
​
 // 应用 websocket 协定
 //ws://server:port/context_path
 // 参数指的是 contex_path
 pipeline.addLast(new WebSocketServerProtocolHandler("/world"));
 //websocket 定义了传递数据的中 frame 类型,这里应用 TextWebSocketFrame 并自定义一个 handler
 pipeline.addLast(new TextWebSocketFrameHandler());
 }
}
public class TextWebSocketFrameHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
 /**
 * 通道列表 用于寄存通道
 */
 public static CopyOnWriteArrayList<Channel> channelList = new CopyOnWriteArrayList<Channel>();
​
 @Override
 protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
​
 /**
 * writeAndFlush 接管的参数类型是 Object 类型,然而个别咱们都是要传入管道中传输数据的类型,比方咱们以后的 demo
 * 传输的就是 TextWebSocketFrame 类型的数据
 */
 System.out.println(msg.text());
 // 遍历通道 list,向非以后通道发送音讯
 channelList.forEach(channel -> {if (channel != ctx.channel()){channel.writeAndFlush(new TextWebSocketFrame(ctx.channel().id().asShortText()+":" +msg.text()));
 }
 else {channel.writeAndFlush(new TextWebSocketFrame("我:" +msg.text()));
 }
 }
 );
 }
​
 /**
 * channel add 后触发, 向 channelList 增加新退出的通道
 *
 * @param ctx ctx
 * @throws Exception 异样
 */
 @Override
 public void handlerAdded(ChannelHandlerContext ctx) throws Exception {channelList.forEach(channel -> channel.writeAndFlush(new TextWebSocketFrame(ctx.channel().id().asShortText()+"上线了")));
 channelList.add(ctx.channel());
 }
​
 /**
 * channel 连贯断开时触发,猜想是 TCP 断开时触发回调 发送连贯断开事件
 *
 * @param ctx ctx
 * @throws Exception 异样
 */
 @Override
 public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {channelList.forEach(channel -> channel.writeAndFlush(new TextWebSocketFrame(ctx.channel().id().asShortText()+"下线了")));
 }
​
 @Override
 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {System.out.println("异样产生");
 ctx.close();}

TextWebSocketFrameHandler继承了 SimpleChannelInboundHandler,SimpleChannelInboundHandler 实际上是一个 ChannelHandlerAdapter,其办法会在入站的时候被调用。这里咱们通过重写handlerAdded 办法,在通道创立后将其退出当 channelList 中,并向其余通道发送成员上线的提示信息。重写 channelRead0 办法,向所有非以后 channel 发送读取到音讯。

前端

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>WebSocket 客户端 </title>
</head>
<body>
<script type="text/javascript">
 var socket;
 // 如果浏览器反对 WebSocket
 if(window.WebSocket){
        // 参数就是与服务器连贯的地址
 socket = new WebSocket("ws://localhost:8005/world");
 // 客户端收到服务器音讯的时候就会执行这个回调办法
 socket.onmessage = function (event) {var ta = document.getElementById("responseText");
 ta.value = ta.value + "n"+event.data;
 }
        // 连贯建设的回调函数
 socket.onopen = function(event){var ta = document.getElementById("responseText");
 ta.value = "连贯开启";
 }
        // 连贯断掉的回调函数
 socket.onclose = function (event) {var ta = document.getElementById("responseText");
 ta.value = ta.value +"n"+"连贯敞开";
 }
    }else{alert("浏览器不反对 WebSocket!");
 }
    // 发送数据
 function send(message){if(!window.WebSocket){return;}
        // 当 websocket 状态关上
 if(socket.readyState == WebSocket.OPEN){socket.send(message);
 }else{alert("连贯没有开启");
 }
    }
</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> 服务器输入:</h3>
 <textarea id ="responseText" style="width: 400px;height: 300px;"></textarea>
 <input type="button" onclick="javascript:document.getElementById('responseText').value=''" value="清空数据">
</form>
</body>
</html>

测试

退出移动版