ScheduledExecutorService

package org.ScheduledExecutorService;

import java.text.SimpleDateFormat;
import java.util.Date;

public class RunnableJob implements Runnable{

    private static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
    
    @Override
    public void run() {

        try {
            Thread.sleep(5000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("The current time is " + sdf.format(new Date()) + ".");
    }

}

package org.ScheduledExecutorService;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.Callable;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ScheduledExecutorServiceTest {

    private static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
    
    private static ScheduledExecutorService executor = Executors.newScheduledThreadPool(10);

    /**
     * 初始化延迟1s开始执行，每隔3s重新执行一次任务。
     */
    public void scheduleAtFixedRateTest() {
        executor.scheduleAtFixedRate(new RunnableJob(), 1, 3, TimeUnit.SECONDS);
    }
    
    /**
     * 初始化时延时1s开始执行，本次执行结束后延迟4s开始下次执行。
     */
    public void scheduleWithFixedDelayTest(){
        executor.scheduleWithFixedDelay(new RunnableJob(), 1, 4, TimeUnit.SECONDS);
    }
    
    public void scheduleRunnableTest(){
        executor.schedule(new RunnableJob(), 3, TimeUnit.SECONDS);
    }
    
    public void scheduleTest(){
/*        executor.schedule(new Callable<V>() {
        }, delay, unit)*/
    }
    public static void main(String[] args) {
        ScheduledExecutorServiceTest sest = new ScheduledExecutorServiceTest();
        System.out.println("start time is " + sdf.format(new Date()));
    //    sest.scheduleAtFixedRateTest();
    //    sest.scheduleWithFixedDelayTest();
        sest.scheduleRunnableTest();
    }
}