Netty多人聊天室

在简单聊天室的代码中修改ChatServerHandler类，就可以模拟多人聊天的功能

1package com.cppdy.server;
2
3import io.netty.channel.Channel;
4import io.netty.channel.ChannelHandlerContext;
5import io.netty.channel.SimpleChannelInboundHandler;
6import io.netty.channel.group.ChannelGroup;
7import io.netty.channel.group.DefaultChannelGroup;
8import io.netty.util.concurrent.GlobalEventExecutor;
9
10public class ChatServerHandler extends SimpleChannelInboundHandler<String> {
11
12    // 存放channel的集合
13    public static ChannelGroup channels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
14
15    @Override
16    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
17
18        System.out.println(msg);
19
20        for (Channel channel : channels) {
21            if (!channel.equals(ctx.channel())) {
22                channel.writeAndFlush("[Server]-" + "[" + channel.remoteAddress() + "]" + msg);
23            }
24        }
25
26    }
27
28    @Override
29    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
30        System.out.println(ctx.channel().remoteAddress()+"--连接上了");
31        channels.add(ctx.channel());
32    }
33
34    @Override
35    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
36        System.out.println(ctx.channel().remoteAddress()+"--退出了");
37        channels.remove(ctx.channel());
38    }
39    
40    @Override
41    public void channelActive(ChannelHandlerContext ctx) throws Exception {
42        System.out.println(ctx.channel().remoteAddress()+"--上线了");
43    }
44    
45    @Override
46    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
47        System.out.println(ctx.channel().remoteAddress()+"--掉线了");
48    }
49    
50    @Override
51    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
52        System.out.println(ctx.channel().remoteAddress()+"--error");
53    }
54
55}

先启动ChatServer类，再启动2次ChatClient类，就可以模拟两个客户端互发消息的功能。