package com.robert.thread;import java.util.Date;public class TestThreadSleep implements Runnable{	public static void main(String[] args) {				TestThreadSleep runnable = new TestThreadSleep();		Thread thread = new Thread(runnable);		thread.start();	}	@Override	public void run() {				System.out.println("i am sleep for a while!");		try {			Date currentTime = new Date();			long startTime = currentTime.getTime();			Thread.sleep(4000);			currentTime = new Date();			long endTime = currentTime.getTime();			System.out.println("休眠时间为："+(endTime-startTime)+"ms");		} catch (InterruptedException e) {			e.printStackTrace();		}	}}