Here you can find the source of sleep()
public static void sleep()
//package com.java2s; //License from project: Apache License public class Main { private final static long MINUTE = 60 * 1000L; public static void sleep() { try {/*w w w . j a v a 2 s . c o m*/ Thread.sleep(MINUTE); } catch (InterruptedException e) { // swallow the exception } } }