Java实现双保险线程的代码实例

public static void startMonitor() {
 System.out.println("启动用户会话检测线程");
 UserMonitor worker = new UserMonitor("WT-UserMonitor");
 CheckThread checker = new CheckThread("WT-UserMonitorCheck",userMonitorIntevalTime);
 DoubleInsuredThead.startDoubleInsuredThead(worker, checker);
}

package com.yx.demo.thread;
 
/**
 * DoubleInsuredThead
 * 双保险线程，每次启动2个相同的线程，互相检测，避免线程死锁造成影响。
 * <p>
 * 两个线程都运行，但只有一个线程执行业务，但都会检测对方的时间戳 如果时间戳超过休眠时间3倍没有更新的话，则重新启动对方线程
 * <p>
 * 代码例子：
 * 一般工作线程由自己实现，继承DoubleInsuredThead，在run2()方法里实现具体需求，和一般线程的run()方法不同，run2()
 * 里不用处理循环和休眠 检测线程已经由CheckThread实现，可以直接使用
 *
 * <pre>
 *  启动用户检测线程
 *  public static void startMonitor() {
 *  System.out.println("启动用户会话检测线程");
 *  UserMonitor worker = new UserMonitor("XX-UserMonitor");
 *  CheckThread checker = new CheckThread("XX-UserMonitorCheck",userMonitorIntevalTime);
 *  DoubleInsuredThead.startDoubleInsuredThead(worker, checker);
 *    }
 * </pre>
 *
 * @author yx
 * @date 2019/12/21 0:36
 */
public abstract class DoubleInsuredThead extends Thread {
 
  /**
   * 默认线程休眠时间为1000毫秒
   */
  public static final long DEFAULT_SLEEP_TIME = 1000;
 
  /**
   * 是否运行本线程
   */
  private boolean running = true;
  /**
   * 线程时间戳，每次run的时候更新
   */
  private long timeStamp = System.currentTimeMillis();
  /**
   * 互相检测的另外一个线程
   */
  DoubleInsuredThead another;
 
  public DoubleInsuredThead(String name) {
    super(name);
  }
 
  /**
   * 子线程的执行业务的方法，相当于Runnable.run()方法
   */
  public abstract void run2();
 
  /**
   * 获得实例，重启线程的时候用
   *
   * @return
   */
  public abstract DoubleInsuredThead newInstance();
 
  /**
   * 启动工作线程，使用默认检测线程
   *
   * @param workerThread
   */
  public static void startDoubleInsuredThead(DoubleInsuredThead workerThread) {
    CheckThread checkerThread =
        new CheckThread(workerThread.getName() + "-checker", workerThread.getSleepTime());
    workerThread.another = checkerThread;
    checkerThread.another = workerThread;
    workerThread.start();
    checkerThread.start();
  }
 
  /**
   * 自定义检测线程的方式启动工作线程，建议使用startDoubleInsuredThead(DoubleInsuredThead workerThread)
   *
   * @param worker 工作线程
   * @param checker 检测线程
   * @deprecated
   */
  public static void startDoubleInsuredThead(DoubleInsuredThead worker,
      DoubleInsuredThead checker) {
    worker.another = checker;
    checker.another = worker;
    worker.start();
    checker.start();
  }
 
  /**
   * 重启线程
   */
  public void restart() {
    System.out.println("线程\"" + getName() + "\"重新启动了");
    // 停止当前线程
    running = false;
    // 启动新线程
    DoubleInsuredThead t = newInstance();
    t.setTimeStamp(System.currentTimeMillis());
    another.another = t;
    t.another = another;
    t.start();
  }
 
  @Override
  public void run() {
    while (running) {
      // 执行子类线程的业务
      run2();
      checkAnother();
      setTimeStamp(System.currentTimeMillis());
 
      try {
        Thread.sleep(getSleepTime());
      } catch (InterruptedException e) {
        e.printStackTrace();
        System.out.println("线程休眠出错：" + e.getMessage());
      }
    }
  }
 
  /**
   * 获得线程休眠的时间，单位毫秒
   *
   * @return
   */
  public long getSleepTime() {
    return DEFAULT_SLEEP_TIME;
  }
 
  /**
   * 对另外一个线程进行检测
   */
  private void checkAnother() {
    if (another.isTimeout()) {
      another.restart();
    }
  }
 
  /**
   * 是否更新时间戳超时
   *
   * @return
   */
  private boolean isTimeout() {
    System.out.println("timeStamp = " + getTimeStamp());
    return System.currentTimeMillis() - getTimeStamp() > getSleepTime() * 3;
  }
 
  /**
   * @param timeStamp the timeStamp to set
   */
  public void setTimeStamp(long timeStamp) {
    this.timeStamp = timeStamp;
  }
 
  /**
   * @return the timeStamp
   */
  public long getTimeStamp() {
    return timeStamp;
  }
 
}

package com.yx.demo.thread;
 
/**
 * CheckThread
 * 双保险线程里专门用来检测的线程
 *
 * @author yx
 * @date 2019/12/21 0:38
 */
public class CheckThread extends DoubleInsuredThead {
 
  /**
   * 检测休眠时间，默认1秒
   */
  private long checkIntevalTime = 1000;
 
  public CheckThread(String name, long checkTime) {
    super(name);
    this.checkIntevalTime = checkTime;
  }
 
  @Override
  public DoubleInsuredThead newInstance() {
    return new CheckThread(getName(), checkIntevalTime);
  }
 
  @Override
  public void run2() {
    // 只打印信息
    System.out.println("线程" + getName() + "完成了工作");
  }
 
  @Override
  public long getSleepTime() {
    return checkIntevalTime;
  }
 
  /**
   * 测试代码
   *
   * @param args
   */
  public static void main(String[] args) {
    CheckThread worker = new CheckThread("worker", 3000);
    DoubleInsuredThead.startDoubleInsuredThead(worker);
  }
}