httpServlet,java web后台服务

package com.utils;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class MyTimer extends Thread {
    
    // 间隔时间：小时
    private int intervalHours;
    
    // 误差(操作所需时间可能导致误差)：分钟
    private int deviationMinute;
    
    // 执行时间
    private String runTime;
    
    public MyTimer(){
        // 参数取得
        intervalHours = 24;
        deviationMinute = 5;
        runTime= "19:30";
    }
    
    public void run() {
        while (!this.isInterrupted()) {// 线程未中断执行循环
        
            // 获取当前时间：HH:mm
            Date now = new Date(); 
            SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm");
            String hours = dateFormat.format(now); 

            // 时间到达
            if(hours.equals(runTime)){
                doRun();
                try {
                    // 长时间休眠:间隔时间-误差
                    Thread.sleep(intervalHours * 3600 * 1000 - deviationMinute * 60 * 1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }else{
                try {
                    // 等待间隔:30s
                    Thread.sleep(30000);
                    System.out.println(hours);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * 处理
     */
    private void doRun() {
    }
}

package com.utils;

import javax.servlet.http.HttpServlet;

public class MyServlet extends HttpServlet{

    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private MyTimer myTimer;  
    public MyServlet(){  
        }  

    public void init(){  
        String str = null;  
        if (str == null && myTimer== null) {  
            myTimer=  new MyTimer();
            
            myTimer.start(); 
        }
　　　　　super.init();  
    }  

    public void destory(){  
        if (myTimer!= null && myTimer.isInterrupted()) {  
            myTimer.interrupt();  
        }
　　　　　super.destroy();  
    }  
}

    <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>com.utils.MyServlet</servlet-class>
        <load-on-startup>9</load-on-startup
　　</servlet>