Timer定时器使用

import java.util.TimerTask;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hi.SpringContextHolder;
import org.nstcrm.customer.model.Company;
import org.nstcrm.customer.service.CompanyManager;
/**
 * 定时执行任务
 * @author ssh_kobe
 */
public class CompanyChangeTask extends TimerTask {
	
	private static Log log = LogFactory.getLog(CompanyChangeTask.class);     
   	 private static boolean isRunning = false;
	@Override
	public void run() {
		if (!isRunning) {
			isRunning = true;
			log.debug("开始执行任务..."); // 开始任务
			
			CompanyManager companyMgr = (CompanyManager)SpringContextHolder.getBean(Company.class);
			companyMgr.modifyCompanys();
			
			log.debug("执行任务完成..."); // 任务完成
			isRunning = false;
		} else {
			log.debug("上一次任务执行还未结束..."); 
		} 
	}
}

import java.util.Timer;

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

import org.apache.commons.lang.time.DateUtils;


public class TaskManager implements ServletContextListener {
	
	/**
	 * 每天的毫秒数
	 */
	public static final long PERIOD_DAY = DateUtils.MILLIS_PER_DAY;
	/**
	 * 一周内的毫秒数
	 */
	public static final long PERIOD_WEEK = PERIOD_DAY * 7;
	/**
	 * 无延迟
	 */
	public static final long NO_DELAY = 0;
	/**
	 * 定时器
	 */
	private Timer timer;
	

	/**
	 * 在Web应用结束时停止任务
	 */
	public void contextDestroyed(ServletContextEvent arg0) {
		timer.cancel(); // 定时器销毁
	}

	/**
	 * 在Web应用启动时初始化任务
	 */
	public void contextInitialized(ServletContextEvent arg0) {
		timer = new Timer("每天更新company数据", true);
		// 每天执行一次
		timer.schedule(new CompanyChangeTask(), NO_DELAY, PERIOD_DAY);
	}
}

web.xml配置：

<!-- 定时器 定时执行的任务 -->
 -<listener> <listener-class>org.util.TaskManager</listener-class> </listener>