java 延时的几种方法方法

Java 延时常见的几种方法 

 

1、 用Thread就不会iu无法终止

new Thread(new Runnable() {
            public void run() {
                while (true) {
                    test();
                    try {
                        Thread.sleep(500);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            private void test() {
                // TODO Auto-generated method stub
            }
            public Runnable start() {
                // TODO Auto-generated method stub
                return null;
            }
        }.start());

2、 或者用现成的

javax.swing.Timer timer = new javax.swing.Timer(500, new ActionListener() {   public void actionPerformed(ActionEvent e) {     repaint();   } }；

timer.start();

3、下面这个方法测试过可以用 java非线程延时

import java.awt.Robot;
import java.util.Date;

public class test {
     public   static   void   main(String[]   args)   throws   Exception{   
         Robot  r   =   new   Robot(); 
         System.out.println( "延时前:"+new Date().toString()  ); 
         r.delay(   2000   );   
         System.out.println(   "延时后:"+new Date().toString()   );   
   }   
}

 

  4、 用这下面的TimeTask类（指定延时）

java里面的sleep()并不能精确定时，TimeTask可以：例下面的小程序：

import java.util.*;

public class test {
    public static void main(String[] args) {
        Timer timer = new Timer();// 实例化Timer类
        timer.schedule(new TimerTask() {
            public void run() {
                System.out.println("退出");
                this.cancel();
            }
        }, 5000);// 这里百毫秒
        System.out.println("本程序存在5秒后自动退出");
    }
}

 5.用concurrent包的TimeUnit类延时sleep()方法延时

package concurrency;
//: concurrency/SleepingTask.java
// Calling sleep() to pause for a while.
import java.util.concurrent.*;

public class SleepingTask extends LiftOff {
  public void run() {
    try {
      while(countDown-- > 0) {
        System.out.print(status());
        // Old-style:
        // Thread.sleep(100);
        // Java SE5/6-style:
        TimeUnit.MILLISECONDS.sleep(100);//MILLISECONDS表示以毫秒为单位延时
      }
    } catch(InterruptedException e) {
      System.err.println("Interrupted");
    }
  }
  public static void main(String[] args) {
    ExecutorService exec = Executors.newCachedThreadPool();
    for(int i = 0; i < 5; i++)
      exec.execute(new SleepingTask());
    exec.shutdown();
  }
} /* Output:
#0(9), #1(9), #2(9), #3(9), #4(9), #0(8), #1(8), #2(8), #3(8), #4(8), #0(7), #1(7), #2(7), #3(7), #4(7), #0(6), #1(6), #2(6), #3(6), #4(6), #0(5), #1(5), #2(5), #3(5), #4(5), #0(4), #1(4), #2(4), #3(4), #4(4), #0(3), #1(3), #2(3), #3(3), #4(3), #0(2), #1(2), #2(2), #3(2), #4(2), #0(1), #1(1), #2(1), #3(1), #4(1), #0(Liftoff!), #1(Liftoff!), #2(Liftoff!), #3(Liftoff!), #4(Liftoff!),
*///:~