taskmanager.java

web版的进销存系统

package jxc.util;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;   

import java.sql.ResultSet;
import java.util.*;   

import jxc.com.DBConnect;

public class TaskManager implements ServletContextListener   {   
	private Timer timer = null;   
	BFTask bfTask = null;
	private int bfTime;
	private int bfDay;

	public void contextInitialized(ServletContextEvent event)   {   
		timer = new Timer(true);   
		event.getServletContext().log("定时器已启动");   
		//执行初始化   
		bfTask = new BFTask();
		String Str="Select * from bfpath where id=1";

		try {
			DBConnect dbc = new DBConnect();
			ResultSet rs = dbc.executeQuery(Str);
			if (rs.next()) {
				bfTime = rs.getInt("bfTime");
				bfDay = rs.getInt("bfDay");
			}
			rs.close();
			dbc.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
		//		每天2点备份数据
		Date start=new Date();		
		start.setDate(start.getDate()+1);   
		start.setHours(bfTime);   
		start.setMinutes(0);   
		start.setSeconds(0);        
		System.out.println(start.toLocaleString());             
		long period=bfDay*24*60*60*1000; //时间间隔一天 		
		timer.scheduleAtFixedRate(bfTask, start, period);

		event.getServletContext().log("已经添加任务调度表");   
	}   

	public void contextDestroyed(ServletContextEvent event)   {   
		timer.cancel();   
		//释放资源。。。。。。。。。。   
		event.getServletContext().log("定时器销毁");   
	}   
}