如何使用石英调度器启动具有多个cron触发器的作业

Question

我正在使用Quartz Scheduler在我的Java应用程序中启动作业。我有HelloJob.java 的工作

package com.stackoverflow.test.java;
import java.util.Date;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
public class HelloJob implements Job {
  private String message;
  public HelloJob() {
    Date akt = new Date();
    this.message = "Quartz is running (" + akt + ").";
  }
  @Override
  public void execute(JobExecutionContext context) throws JobExecutionException {
    System.out.println(this.message);
  }
}

我想使用两个不同的cron表达式（此处为：*/5 */3 * * * ?和*/9 */2 * * * ?）来启动此作业。我尝试了以下方法：

package com.stackoverflow.test.java;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.Trigger;
import org.quartz.impl.StdSchedulerFactory;
import org.quartz.TriggerBuilder;
import org.quartz.JobBuilder;
import org.quartz.CronScheduleBuilder;

public class TestQuartz {
  public static void main(String[] args) {
    try {
      Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
      scheduler.start();
      /* ################################################################### */
      JobDetail job = JobBuilder
                      .newJob(HelloJob.class)
                      .withIdentity("job1", "group1")
                      .build();
      CronScheduleBuilder sb1 = CronScheduleBuilder
          .cronSchedule("*/5 */3 * * * ?");
      CronScheduleBuilder sb2 = CronScheduleBuilder
          .cronSchedule("*/9 */2 * * * ?");
      Trigger trigger = TriggerBuilder
          .newTrigger()
          .withIdentity("trigger1", "group1")
          .startNow()
          .withSchedule(sb1)
          .build();
      Trigger trigger2 = TriggerBuilder
          .newTrigger()
          .withIdentity("trigger2", "group1")
          .startNow()
          .withSchedule(sb2)
          .build();
      scheduler.scheduleJob(job, trigger);
      scheduler.scheduleJob(job, trigger2);
      /* ################################################################### */
      Thread.sleep(10 * 60 * 1000);
      System.out.println("FIN");
      /* ################################################################### */
      scheduler.shutdown();
    } catch (SchedulerException se) {
      se.printStackTrace();
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
  }
}

我收到以下异常：

org.quartz.ObjectAlreadyExistsException: Unable to store Job : 'group1.job1', because one already exists with this identification.
    at org.quartz.simpl.RAMJobStore.storeJob(RAMJobStore.java:279)
    at org.quartz.simpl.RAMJobStore.storeJobAndTrigger(RAMJobStore.java:251)
    at org.quartz.core.QuartzScheduler.scheduleJob(QuartzScheduler.java:886)
    at org.quartz.impl.StdScheduler.scheduleJob(StdScheduler.java:249)
    at com.stackoverflow.test.java.TestQuartz.main(TestQuartz.java:47)

用几个触发器启动一个作业是不可能的吗？我能以某种方式生成一个考虑多个cron表达式的时间表吗？

Answer 1

您必须使用TriggerBuilder的forJob(JobKey jobKey)方法为作业分配更多触发器。

Trigger trigger = TriggerBuilder.newTrigger().forJob(job.getKey()). ...
scheduler.scheduleJob(trigger)

在您的情况下，应用以下修改：

/* ... */
Trigger trigger2 = TriggerBuilder
    .newTrigger()
    .forJob(job.getKey())
    .withIdentity("trigger2", "group1")
    .startNow()
    .withSchedule(sb2)
    .build();
/* ... */
scheduler.scheduleJob(trigger2);
/* ... */