實現定時任務 需要quartz-1.5.1.jar和commons-logging-1.1.jar。
2.定義定時任務配置類
該類主要進行定時任務時間的設置和設置對應的定時任務類。
import org.quartz.CronTrigger;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.impl.StdSchedulerFactory;
public class Test{
/**
* 定時任務
*/
public static void cleanUpJob() {
try {
JobDetail jobDetail = new JobDetail();
jobDetail.setName("cleanup");
jobDetail.setJobClass(PrintJob.class);
CronTrigger trigger = new CronTrigger();
trigger.setName("cleanupTrigger");
trigger.setJobName("cleanup");
trigger.setCronExpression("0/5 * * * * ?");
Scheduler sch = StdSchedulerFactory.getDefaultScheduler();
sch.scheduleJob(jobDetail, trigger);
sch.start();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 修改定時任務時間
*/
public static void modifyJobTime(String triggerName, String time) {
System.out.println("modify~~~~~~~~~~~~~~~~");
try {
Scheduler sched = StdSchedulerFactory.getDefaultScheduler();
System.out.println("triggerName " + triggerName);
CronTrigger trigger = (CronTrigger) sched.getTrigger(triggerName, Scheduler.DEFAULT_GROUP);
if(trigger == null) {
return;
}
String oldTime = trigger.getCronExpression();
System.out.println("oldTime " + oldTime);
if (!oldTime.equalsIgnoreCase(time)) {
System.out.println("time " + time);
// 修改時間
trigger.setCronExpression(time);
}
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
public static void main(String[] args) {
cleanUpJob();
modifyJobTime("cleanupTrigger", "0/2 * * * * ?");
}
}
3.定時任務類
該類主要定義定時任務執行的內容。
import java.text.SimpleDateFormat;
import java.util.Date;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
public class PrintJob implements Job{
@Override
public void execute(JobExecutionContext arg0) throws JobExecutionException {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
String time = sdf.format(new Date());
System.out.println("print job" + time);
}
}
4.輸出結果
modify~~~~~~~~~~~~~~~~
triggerName cleanupTrigger
oldTime 0/5 * * * * ?
time 0/2 * * * * ?
print job2014-12-03 17:06:40.031
print job2014-12-03 17:06:42.015
print job2014-12-03 17:06:44.016
print job2014-12-03 17:06:46.019
print job2014-12-03 17:06:48.019
print job2014-12-03 17:06:50.020
從輸出的結果中可以看到，原本的定時任務為每5秒執行壹次，但是由於後面對定時任務表達式做了修改，所以後來安照修改後的每2秒執行壹次。