Quartz Scheduler - Pass Parameters to Job
November 20, 2023
JobDataMap
org.quartz.JobDataMap is used to put and get values for a job instance. If the job is annotated with@PersistJobDataAfterExecution, then after job execution job states are re-persisted. JobDataMap is used to pass parameters to scheduled job. Using JobDetail instance we get the instance of JobDataMap and then add the values which needs to pass to scheduled job.
JobDataMap jobDataMap= jobDetail.getJobDataMap() jobDataMap.put(PrintNameJob.NAME, "RAM");
JobDataMap values, we can do as follows.
JobDataMap dataMap = context.getJobDetail().getJobDataMap(); String name = dataMap.getString(NAME);
JobDetail instance by JobExecutionContext and get the instance of JobDataMap using JobDetail instance.
@PersistJobDataAfterExecution and @DisallowConcurrentExecution Annotations
@PersistJobDataAfterExecution annotation which is clear by its name, is used onJob implementing class to update JobDataMap while execution and can re-store it after execution. While doing such task, concurrent execution should be avoided. So we must also annotate our class with @DisallowConcurrentExecution annotation.
Create a Job
For the demo, we are creating a job in which we will access two parameters fromJobDataMap passed while scheduling the job, one is the name and another is count. While execution, we will update count and persist it again in JobDataMap. In every execution of job, the new instance of job is created. To check it, I have taken a member variable with the value "new object" and within execution we have changed its value. What we see in output is that this will always be "new object", means every time, new instance of job is created.
PrintNameJob.java
package com.concretepage.job;
import org.quartz.DisallowConcurrentExecution;
import org.quartz.Job;
import org.quartz.JobDataMap;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.JobKey;
import org.quartz.PersistJobDataAfterExecution;
@PersistJobDataAfterExecution
@DisallowConcurrentExecution
public class PrintNameJob implements Job {
public static final String NAME = "name";
public static final String COUNT = "count";
private String flag = "new object";
@Override
public void execute(JobExecutionContext context)
throws JobExecutionException {
JobDataMap dataMap = context.getJobDetail().getJobDataMap();
//fetch parameters from JobDataMap
String name = dataMap.getString(NAME);
int count = dataMap.getInt(COUNT);
JobKey jobKey = context.getJobDetail().getKey();
System.out.println(jobKey+": "+ name+"-"+count+": flag="+flag);
count++;
//add next counter to JobDataMap
dataMap.put(COUNT, count);
flag= "object changed";
}
}
Run Scheduler with passing parameters to Job
We will create two job details and trigger for the demo and will be added to scheduler for race condition. Both will access the same job for 3 rounds with 5 seconds time interval. We will pass two parameters, name and count with different values usingJobDataMap.
PassParameterByJobDataMap.java
package com.concretepage;
import java.util.Calendar;
import java.util.Date;
import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleScheduleBuilder;
import org.quartz.SimpleTrigger;
import org.quartz.TriggerBuilder;
import org.quartz.impl.StdSchedulerFactory;
import com.concretepage.job.PrintNameJob;
public class PassParameterByJobDataMap {
public static void main(String[] args) throws SchedulerException {
SchedulerFactory schedulerFactory = new StdSchedulerFactory();
Scheduler scheduler = schedulerFactory.getScheduler();
//create first JobDetail and Trigger
JobDetail jobDetail = JobBuilder.newJob(PrintNameJob.class).withIdentity("ramjob", "ourgroup").build();
SimpleTrigger trigger = TriggerBuilder.newTrigger().withIdentity("ramtrigger", "ourgroup")
.startAt(new Date(Calendar.getInstance().getTimeInMillis()+ 5000))
.withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(5)
.withRepeatCount(3)).build();
//add passing parameters to JobDataMap for first JobDetail
jobDetail.getJobDataMap().put(PrintNameJob.NAME, "RAM");
jobDetail.getJobDataMap().put(PrintNameJob.COUNT, 11);
scheduler.scheduleJob(jobDetail, trigger);
//create second JobDetail and Trigger
jobDetail = JobBuilder.newJob(PrintNameJob.class).withIdentity("rahimjob", "ourgroup").build();
trigger = TriggerBuilder.newTrigger().withIdentity("rahimtrigger", "ourgroup")
.startAt(new Date(Calendar.getInstance().getTimeInMillis()+ 5000))
.withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(5)
.withRepeatCount(3)).build();
//add passing parameters to JobDataMap for second JobDetail
jobDetail.getJobDataMap().put(PrintNameJob.NAME, "RAHIM");
jobDetail.getJobDataMap().put(PrintNameJob.COUNT, 21);
scheduler.scheduleJob(jobDetail, trigger);
scheduler.start();
try {
//wait for 30 seconds to finish the job
Thread.sleep(30000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//shutdown scheduler gracefully
scheduler.shutdown(true);
}
}
ourgroup.ramjob: RAM-11: flag=new object ourgroup.rahimjob: RAHIM-21: flag=new object ourgroup.ramjob: RAM-12: flag=new object ourgroup.rahimjob: RAHIM-22: flag=new object ourgroup.ramjob: RAM-13: flag=new object ourgroup.rahimjob: RAHIM-23: flag=new object ourgroup.ramjob: RAM-14: flag=new object ourgroup.rahimjob: RAHIM-24: flag=new object
