一、handler定义：

package handler;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

public class MyChatServerHandler3 extends ChannelInboundHandlerAdapter {
    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        System.out.println(evt);
        super.userEventTriggered(ctx, evt);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {

        System.out.println("received: " + msg);
    }
}

二、定义Initializer

package initializer;

import handler.MyChatServerHandler;
import handler.MyChatServerHandler3;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.Delimiters;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.timeout.IdleStateHandler;
import io.netty.util.concurrent.GlobalEventExecutor;

import java.util.concurrent.TimeUnit;

public class MyChatServerInitializer3 extends ChannelInitializer<SocketChannel>{


    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        System.out.println("in initChannel......");
        //ch.pipeline().addLast(new DelimiterBasedFrameDecoder(4096,Delimiters.lineDelimiter()));
        ch.pipeline().addLast(new IdleStateHandler(3, 5, 6));
        ch.pipeline().addLast(new StringDecoder());
        ch.pipeline().addLast(new StringEncoder());

        ch.pipeline().addLast(new MyChatServerHandler3());

    }





}

三、定义server启动类，在pipeline中添加IdleStateHandler

package server;

import handler.MyChatServerHandler;
import initializer.MyChatServerInitializer;
import initializer.MyChatServerInitializer;
import initializer.MyChatServerInitializer3;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.ServerSocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;

public class MyChatServer3 {

    public static void main(String[] args) throws Exception {
        EventLoopGroup bossGroup =new NioEventLoopGroup();
        EventLoopGroup workerGroup =new NioEventLoopGroup();

        try
        {

            ServerBootstrap serverBootstrap=new ServerBootstrap();
            serverBootstrap.group(bossGroup,workerGroup);
            serverBootstrap.channel(NioServerSocketChannel.class);
            serverBootstrap.handler(new LoggingHandler(LogLevel.INFO));
            serverBootstrap.childHandler(new MyChatServerInitializer3());
            ChannelFuture channelFuture=serverBootstrap.bind(9999).sync();
            channelFuture.channel().closeFuture().sync();




        }
        finally
        {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }


    }

}

当客户端连接之后，如果一段时间不发送数据，则服务器端会触发IdleStateEvent并被处理