Netty 5, websocket, websocket羣發消息

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package com.yxw.task;

import java.net.SocketAddress;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;

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

public class CustomTextFrameHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
	//DefaultChannelGroup recipients = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
	private ChannelGroup recipients;

	 
	public CustomTextFrameHandler(ChannelGroup  recipients) {
		this.recipients= recipients;
	}
	
    @Override
    protected void messageReceived(ChannelHandlerContext ctx, TextWebSocketFrame frame) throws Exception {
        String request = frame.text();
        
        //ctx.channel().writeAndFlush(new TextWebSocketFrame(request.toUpperCase()));
        System.out.println("size:"+recipients.size());
        recipients.write(new TextWebSocketFrame(request.toUpperCase()));
        
    }
    
 
    
    @Override
    public void  channelActive(ChannelHandlerContext ctx){
    		recipients.add(ctx.channel());
    		System.out.println("connect:"+recipients.size());
    }
    
    @Override
    public void handlerRemoved(ChannelHandlerContext ctx){
        try {
            recipients.remove(ctx.channel());
            System.out.println("刪除channel成功"+recipients.size());
        } catch (Exception ex) {
            System.out.println("刪除channel失敗"+ex.getMessage());
        }
     }      
  
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}

 以上是 CustomTextFrameHandler.java 內容，

 

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License, version
 * 2.0 (the "License"); you may not use this file except in compliance with the
 * License. You may obtain a copy of the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.yxw.task;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.group.DefaultChannelGroup;
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.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.util.concurrent.GlobalEventExecutor;

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

/**
 * A WebSocket Server that respondes to requests at:
 *
 * <pre>
 * http://localhost:8080/websocket
 * </pre>
 *
 * The example differs from many of the other examples in Netty in that is does
 * not have an acomponying client. Instead a html page is provided that
 * interacts with this server. <br>
 * Open up the following file a web browser that supports WebSocket's:
 *
 * <pre>
 * example/src/main/resources/websocketx/html5/websocket.html
 * </pre>
 *
 * The html page is very simple were you simply enter some text and the server
 * will echo the same text back, but in uppercase. You, also see getStatus messages
 * in the "Response From Server" area when client has connected, disconnected
 * etc.
 *
 */
public class WebSocketServer {

    private final int port;

    public WebSocketServer(int port) {
        this.port = port;
    }

    public void run() throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            final ServerBootstrap sb = new ServerBootstrap();
            sb.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             .childHandler(new ChannelInitializer<SocketChannel>() {
                @Override
                public void initChannel(final SocketChannel ch) throws Exception {
                    ch.pipeline().addLast(
                        new HttpResponseEncoder(),
                        new HttpRequestDecoder(),
                        new HttpObjectAggregator(65536),
                        new WebSocketServerProtocolHandler("/websocket"),
                        new CustomTextFrameHandler(new DefaultChannelGroup(GlobalEventExecutor.INSTANCE)));
                }
            }).option(ChannelOption.SO_BACKLOG, 65536)         
            .childOption(ChannelOption.SO_KEEPALIVE, true)
            .childOption(ChannelOption.TCP_NODELAY, true);
            //.childOption(ChannelOption.SO_BROADCAST, true);
            //bootstrap.setOption("child.reuseAddress", true);		
            //bootstrap.setOption("child.tcpNoDelay", true);		
            //bootstrap.setOption("child.keepAlive", true);
            
            final Channel ch = sb.bind(port).sync().channel();
            System.out.println("Web socket server started at port " + port);

            ch.closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        int port;
        if (args.length > 0) {
            port = Integer.parseInt(args[0]);
        } else {
            port = 8080;
        }
        new WebSocketServer(port).run();
    }

}

  以上是WebSocketServer.java 的內容， 基本是Netty5 自帶的例子改了一點點，

 

 

運行之後，命令行輸出：

 

Web socket server started at port 8080

connect:1

size:1

connect:1

size:1

 

 

recipients.size() 始終是1， 於是這個程序不能實現廣播， 不知道問題出自哪裏？

 

這裏忍不住吐槽一下：

1. Netty 不同版本，其接口，方法改變很大，新版本不兼容舊的，一些網上搜到的代碼基本都不能用；

2. Netty 上的github上的代碼是最新的， 所以想運行example必須用最新版本；

3. 網上的資料太少了；

4. 官方的User guide 和example實在too simple了， 弄了半天還是幾個hellow world， 麻煩有點深度寫點有用的東西行不， 畢竟項目是用來解決實際問題了， 不是用來寫hellow world；