Java心跳包功能TCP实现

import java.io.IOException; import java.io.InputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.net.Socket; import java.net.UnknownHostException; public class Client { private String serverIp = "127.0.0.1"; private int port = 65432; private Socket socket; private volatile boolean running = false; public static void main(String[] args) throws UnknownHostException, IOException { Client client = new Client(); client.start(); } public void start() throws UnknownHostException, IOException { // 已经运行 if (running) return; socket = new Socket(serverIp, port); System.out.println("本地端口：" + socket.getLocalPort()); socket.setKeepAlive(true); running = true; new Thread(new KeepAliveWatchDog()).start(); new Thread(new ReceiveWatchDog()).start(); } public void sendObject(Object obj) throws IOException { ObjectOutputStream oos = new ObjectOutputStream( socket.getOutputStream()); oos.writeObject(obj); oos.flush(); } public void stop() { if (running) running = false; if (socket != null) { try { socket.close(); } catch (IOException e) { e.printStackTrace(); }finally{ socket = null; } } System.out.println("关闭客户端"); } class KeepAliveWatchDog implements Runnable { private long checkDelay = 100; // 每隔10秒发送一个心跳包 long keepAliveDelay = 10000; private long lastSendTime = System.currentTimeMillis(); @Override public void run() { while (running) { if (System.currentTimeMillis() - lastSendTime > keepAliveDelay) { try { Client.this.sendObject(new KeepAlive()); lastSendTime = System.currentTimeMillis(); } catch (IOException e) { e.printStackTrace(); Client.this.stop(); } } else { try { Thread.sleep(checkDelay); } catch (InterruptedException e) { e.printStackTrace(); Client.this.stop(); } } } } } class ReceiveWatchDog implements Runnable { private long checkDelay = 100; // 这个时间要比心跳包发送间隔长一点， // 否则可能导致没有获取到服务器端的响应而结束 long keepAliveDelay = 11000; private long lastReceiveTime = System.currentTimeMillis(); @Override public void run() { while (running) { if (System.currentTimeMillis() - lastReceiveTime > keepAliveDelay) { Client.this.stop(); } else { try { InputStream in = socket.getInputStream(); if (in.available() > 0) { ObjectInputStream ois = new ObjectInputStream(in); Object obj = ois.readObject(); lastReceiveTime = System.currentTimeMillis(); System.out.println("接收服务器端的信息来自"+socket.getPort()+"端口："+obj); } else { Thread.sleep(checkDelay); } } catch (Exception e) { e.printStackTrace(); Client.this.stop(); } } } } } }