How to dynamically schedule a Spring Batch job with ThreadPoolTaskScheduler - spring

Question

I have a Spring Batch application in which I want to schedule jobs calls.
The scheduling interval is not known at build so I can't just annotate my Job with #Scheduled.This led me to use a ThreadPoolTaskScheduler.
The thing is the method schedule takes a Runnable as a parameter. Is it possible to schedule jobs this way ?
I can call the job directly from the following service but I can't schedule it.
Here is my the background of my problem, I tried to make it simple :
#Service
public class ScheduledProcessor{
private final ThreadPoolTaskScheduler threadPoolTaskScheduler;
private Application application;
#Autowired
public ScheduledProcessor(ThreadPoolTaskScheduler threadPoolTaskScheduler, Application application){
this.threadPoolTaskScheduler = threadPoolTaskScheduler;
this.application = application;
scheduledTasks = new ArrayList();
Trigger trigger = new CronTrigger("0/6 * * * * *");
//Here I am trying to schedule my job.
//The following line is wrong because a Job can't be cast to a Runnable but I wanted to show the intended behaviour.
threadPoolTaskScheduler.schedule((Runnable) application.importUserjob, trigger);
System.out.println("Job launch !");
}
And here is the JobBuilderFactory :
#Bean
public Job importUserJob(JobBuilderFactory jobs, Step s1, Step s2) {
return jobs.get("importUserJob")
.incrementer(new RunIdIncrementer())
.flow(s1)
.end()
.build();
}
I understand (well, I'm even not sure about that) that I can't directly cast a Job to a Runnable but is it possible to convert it in any way ? Or can you give me some advice about what to use for being able to dynamically schedule spring batch jobs ?
In case that changes something, I also need to be able to restart / skip my steps, as I currently can with the threadPoolTaskScheduler.
Thank you in advance for any help or hint you could provide.

Answer 1

I finally got how to do it !
I created a class which implements Runnable (and for convenience, extends Thread, which avoid the need to implement all of Runnable classes).
#Component
public class MyRunnableJob extends Thread implements Runnable{
private Job job;
private JobParameters jobParameters;
private final JobOperator jobOperator;
#Autowired
public MyRunnableJob(JobOperator jobOperator) {
this.jobOperator = jobOperator;
}
public void setJob(Job job){
this.job=job;
}
#Override
public void run(){
try {
String dateParam = new Date().toString();
this.jobParameters = new JobParametersBuilder().addString("date", dateParam).toJobParameters();
System.out.println("jobName : "+job.getName()+" at "+dateParam);
jobOperator.start(job.getName(), jobParameters.toString());
} catch (NoSuchJobException | JobInstanceAlreadyExistsException | JobParametersInvalidException ex) {
Logger.getLogger(MyRunnableJob.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
In my ScheduledProcessor class, I set a Job to myRunnable class and then pass it as a parameter of the schedule method.
public class SchedulingProcessor {
//Autowired fields :
private final JobLauncher jobLauncher;
private final Job importUserJob;
private final ThreadPoolTaskScheduler threadPoolTaskScheduler;
private final MyRunnableJob myRunnableJob;
//Other fields :
private List<ScheduledFuture> scheduledTasks;
#Autowired
public SchedulingProcessor(JobLauncher jobLauncher, Job importUserJob, ThreadPoolTaskScheduler threadPoolTaskScheduler, MyRunnableJob myRunnableJob) throws Exception {
this.jobLauncher=jobLauncher;
this.importUserJob=importUserJob;
this.threadPoolTaskScheduler=threadPoolTaskScheduler;
this.myRunnableJob=myRunnableJob;
Trigger trigger = new CronTrigger("0/6 * * * * *");
myRunnableJob.setJob(this.importUserJob);
scheduledTasks = new ArrayList();
scheduledTasks.add(this.threadPoolTaskScheduler.schedule((Runnable) myRunnableJob, trigger));
}
}
The scheduledTasks list is just to keep a control over the tasks I just scheduled.
This trick enabled me to dynamically (thanks to ThreadPoolTaskScheduler) schedule Spring Batch Jobs encapsulated in a class implementing Runnable. I wish it can help someone in the same case as mine.

Answer 2

Heres another way to trigger them from your spring context.
Job emailJob = (Job) applicationContext.getBean("xyzJob");
JobLauncher launcher = (JobLauncher) applicationContext
.getBean("jobLauncher");
launcher.run(emailJob, new JobParameters());