netty 5 心跳

netty 5 心跳

package com.server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelOption; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.codec.string.StringDecoder; import io.netty.handler.codec.string.StringEncoder; import io.netty.handler.timeout.IdleStateHandler; public class server { public static void main(String[] args){ // 创建一个 server 服务 ServerBootstrap server = new ServerBootstrap(); EventLoopGroup boss = new NioEventLoopGroup(); EventLoopGroup worker = new NioEventLoopGroup(); // 绑定 try{ server.group(boss, worker); server.channel( NioServerSocketChannel.class); server.childHandler(new ChannelInitializer<Channel>() { @Override protected void initChannel(Channel ch) throws Exception { ch.pipeline().addLast(new IdleStateHandler(5, 5, 10)); ch.pipeline().addLast(new StringDecoder()); ch.pipeline().addLast(new StringEncoder()); ch.pipeline().addLast(new ServerHandler()); } }); //netty3中对应设置如下 //bootstrap.setOption("backlog", 1024); //bootstrap.setOption("tcpNoDelay", true); //bootstrap.setOption("keepAlive", true); //设置参数，TCP参数 server.option(ChannelOption.SO_BACKLOG, 2048);//serverSocketchannel的设置，链接缓冲池的大小 server.childOption(ChannelOption.SO_KEEPALIVE, true);//socketchannel的设置,维持链接的活跃，清除死链接 server.childOption(ChannelOption.TCP_NODELAY, true);//socketchannel的设置,关闭延迟发送  ChannelFuture future = server.bind(10001); System.out.println("start！"); //等待服务端关闭  future.channel().closeFuture().sync(); }catch(Exception e){ e.printStackTrace(); }finally{ worker.shutdownGracefully(); boss.shutdownGracefully(); } } }

ServerHandler  代码

package com.server;

import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.timeout.IdleState; import io.netty.handler.timeout.IdleStateEvent; public class ServerHandler extends SimpleChannelInboundHandler<String> { @Override public void userEventTriggered(final ChannelHandlerContext ctx, Object evt) throws Exception { if(evt instanceof IdleStateEvent){ IdleStateEvent event = (IdleStateEvent)evt; if(event.state() == IdleState.ALL_IDLE){ System.out.println("你很久没有联系了"); ChannelFuture future = ctx.writeAndFlush("you will close"); future.addListener( new ChannelFutureListener(){ @Override public void operationComplete(ChannelFuture future) throws Exception { // TODO Auto-generated method stub  ctx.channel().close(); } }); } }else{ super.userEventTriggered(ctx, evt); } } @Override protected void messageReceived(ChannelHandlerContext ctx, String msg) throws Exception { System.out.println(msg); ctx.channel().writeAndFlush("hi"); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { // TODO Auto-generated method stub super.exceptionCaught(ctx, cause); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { // TODO Auto-generated method stub System.out.println("欢迎链接"); super.channelActive(ctx); } @Override public void channelInactive(ChannelHandlerContext ctx) throws Exception { // TODO Auto-generated method stub System.out.println("断开链接"); super.channelInactive(ctx); } }

注意需要引入 netty 5 的jar包

ch.pipeline().addLast(new IdleStateHandler(5, 5, 10));  给管道加入一个心跳事件，  5 读超时 5写超时 10 读写超时   超过5秒没有读就会发起一个读超时事件
Handler 中的 userEventTriggered  这个方法为心跳触发事件，当事件类型为 IdleStateEvent  为超时类型事件  当返回的状态为 IdleState.ALL_IDLE  为读写超时