定时器经常在项目中用到，定制执行某些操作，比如爬虫就需要定时加载种子等操作，之前一直用spring的定制器
近期做项目发现，jdk有很简单的提供 代码如下
1 /*
2 * Copyright (c) 2014-2024 . All Rights Reserved.
3 *
4 * This software is the confidential and proprietary information of
5 * LoongTao. You shall not disclose such Confidential Information
6 * and shall use it only in accordance with the terms of the agreements
7 * you entered into with LoongTao.
8 *
9 */
10 package com.loongtao.dmscrawler.temp;
11
12 import java.util.Timer;
13 import java.util.TimerTask;
14
15 /**
16 * @declare:测试定时器 <br>
17 * @author: cphmvp
18 * @version: 1.0
19 * @date: 2014-3-14上午11:21:36
20 */
21 public class TimeTest {
22 public static void main(String[] args) {
23 System.out.println("start");
24 new Timer().schedule(new TestTask(), 0, 1000 * 60 * 60);
25 System.out.println("end");
26
27 }
28
29 static class TestTask extends TimerTask {
30 TestTask() {
31 // 空构造器
32 }
33
34 @Override
35 public void run() {
36 System.out.println(1);
37 }
38
39 }
40 }
jdk源码参考 很容易看懂的 ，不解释
1 * @param task task to be scheduled.
2 * @param delay delay in milliseconds before task is to be executed.
3 * @param period time in milliseconds between successive task executions.
4 * @throws IllegalArgumentException if <tt>delay</tt> is negative, or
5 * <tt>delay + System.currentTimeMillis()</tt> is negative.
6 * @throws IllegalStateException if task was already scheduled or
7 * cancelled, timer was cancelled, or timer thread terminated.
8 */
9 public void schedule(TimerTask task, long delay, long period) {
10 if (delay < 0)
11 throw new IllegalArgumentException("Negative delay.");
12 if (period <= 0)
13 throw new IllegalArgumentException("Non-positive period.");
14 sched(task, System.currentTimeMillis()+delay, -period);
15 }