java 任务，定时器

package com.quartz.text; import java.io.IOException; import java.text.ParseException; import java.util.ArrayList; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.Logger; import org.quartz.CronExpression; import org.quartz.CronTrigger; import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.SchedulerFactory; import org.quartz.Trigger; import org.quartz.TriggerUtils; public class JobServlet extends HttpServlet { private static final long serialVersionUID = -1307372828908205510L; private Logger log; private SchedulerFactory schedFact; private Scheduler sched; public JobServlet(){ } public void init() throws ServletException { schedFact = new org.quartz.impl.StdSchedulerFactory(); try { sched = schedFact.getScheduler(); JobDetail jobDetail = new JobDetail("myJob",sched.DEFAULT_GROUP, TestJob.class); CronTrigger cronTrigger = new CronTrigger("cronTrigger", "triggerGroup"); String patternStr = "0 0 12 * * ?"; CronExpression cronExpression; try { cronExpression = new CronExpression(patternStr); cronTrigger.setCronExpression(cronExpression); } catch (ParseException e) { e.printStackTrace(); } sched.unscheduleJob("cronTrigger","triggerGroup"); sched.scheduleJob(jobDetail, cronTrigger); sched.start(); } catch (SchedulerException e) { e.printStackTrace(); } } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("doGet()========"); } public void destroy() { System.out.println("=========job destory========="); try { sched.shutdown(true); System.out.println("job end"); } catch (Exception ex) { log.error("The quartz exception JobServlet.destroy()" + ex, ex); } } }