java_Timer_schedule jdk自带定时器

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 /*   
 * Copyright (c) 2014-2024 . All Rights Reserved.   
 *   
 * This software is the confidential and proprietary information of   
 * LoongTao. You shall not disclose such Confidential Information   
 * and shall use it only in accordance with the terms of the agreements   
 * you entered into with LoongTao.   
 *   
 */
package com.loongtao.dmscrawler.temp;

import java.util.Timer;
import java.util.TimerTask;

/**
 * @declare:测试定时器 <br>
 * @author: cphmvp
 * @version: 1.0
 * @date: 2014-3-14上午11:21:36
 */
public class TimeTest {
    public static void main(String[] args) {
        System.out.println("start");
        new Timer().schedule(new TestTask(), 0, 1000 * 60 * 60);
        System.out.println("end");

    }

    static class TestTask extends TimerTask {
        TestTask() {
            // 空构造器
        }

        @Override
        public void run() {
            System.out.println(1);
        }

    }
}

jdk源码参考 很容易看懂的 ，不解释

  * @param task   task to be scheduled.
     * @param delay  delay in milliseconds before task is to be executed.
     * @param period time in milliseconds between successive task executions.
     * @throws IllegalArgumentException if <tt>delay</tt> is negative, or
     *         <tt>delay + System.currentTimeMillis()</tt> is negative.
     * @throws IllegalStateException if task was already scheduled or
     *         cancelled, timer was cancelled, or timer thread terminated.
     */
    public void schedule(TimerTask task, long delay, long period) {
        if (delay < 0)
            throw new IllegalArgumentException("Negative delay.");
        if (period <= 0)
            throw new IllegalArgumentException("Non-positive period.");
        sched(task, System.currentTimeMillis()+delay, -period);
    }