java - 每 5 分钟更新一次变量的值

Question

我有一个变量，其值需要根据条件每 5 分钟更新一次。我知道我需要启动一个不同的线程。但我该怎么做呢？

Answer 1

使用ScheduledThreadPoolExecutor

public class Main{
 public static void main(String args[]) {
   ScheduledThreadPoolExecutor stpe = new ScheduledThreadPoolExecutor(2);    
   stpe.scheduleAtFixedRate(new YourJob(), 0, 5, TimeUnit.MINUTES);
 }
}

class YourJob implements Runnable {
   public void run() {
   // your task
    System.out.println("Job 1");
  }
}

Answer 2

使用Quartz 调度器

这更容易..安排任务..

java在预定的时间运行程序是一件好事

• Quartz Schedular 功能可推迟任务在给定时间运行
• 循环执行也可用

Answer 3

线程的方式来做到这一点，

Thread t= new Thread(new Runnable() 
    {           
        public void run() 
        {
            while(true)
            {
                try 
                {
                    Thread.sleep(5 * 60 * 1000);
                    //change your variable values as required                       
                } 
                catch (InterruptedException e) 
                {

                }                                   
            }
        }
    });

线程池执行器方式，

public static void main(String args[]) 
    {
        ScheduledThreadPoolExecutor myPool = new ScheduledThreadPoolExecutor(2);    
        myPool.scheduleAtFixedRate(new MyJob(), 0, 5 , TimeUnit.MINUTES);       
    }
    class MyJob implements Runnable
    {
        public void run() 
        {
            //change your variable values as required in this function as this will be invoked every 5 minutes             
        }
    }

定时器实现

Timer timer =new Timer();
        TimerTask task = new TimerTask() 
        {

            @Override
            public void run() 
            {
                //change your variable values as required in this function as this will be invoked every 5 minutes   

            }
        };
        timer.schedule(task, new Date(), 5 * 60 * 1000); //Use this if you want the new task to be invoked after completion of prior task only              
        timer.scheduleAtFixedRate(task, new Date(), 5 * 60 * 1000);//Use this if you want the new task to be invoked after fixed interval 
                                                                   //but will no depend or wait on completion of the prior task 

Answer 4

如果您使用的是 Spring，则可以使用 @Scheduled 注释您的方法，例如：

// Invoke method every 300000 ms (5 minutes)
@Scheduled(fixedDelay=300000)
public void myMethod() {
    // Your code here
}

或者您可以查看 Spring 的文档：http ://docs.spring.io/spring/docs/3.0.x/spring-framework-reference/htmlsingle/spring-framework-reference.html#scheduling-annotation-support-预定的

Answer 5

怎么用java.util.Timer？