/*
* 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("删除channel成功"+recipients.size());
} catch (Exception ex) {
System.out.println("删除channel失败"+ex.getMessage());
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
以上是 CustomTextFrameHandler.java 内容，
/*
* 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 的内容， 基本是Netty5 自带的例子改了一点点，
运行之后，命令行输出：
Web socket server started at port 8080
connect:1
size:1
connect:1
size:1
recipients.size() 始终是1， 于是这个程序不能实现广播， 不知道问题出自哪里？
这里忍不住吐槽一下：
1. Netty 不同版本，其接口，方法改变很大，新版本不兼容旧的，一些网上搜到的代码基本都不能用；
2. Netty 上的github上的代码是最新的， 所以想运行example必须用最新版本；
3. 网上的资料太少了；
4. 官方的User guide 和example实在too simple了， 弄了半天还是几个hellow world， 麻烦有点深度写点有用的东西行不， 毕竟项目是用来解决实际问题了， 不是用来写hellow world；