How to trigger a scheduled Spring Batch Job?

Question

I want to be able to start my job with a REST controller, then when the job is started, it should run on a scheduled basis, until i stop it again with REST.

So this is my Controller:

@RestController
public class LauncherController {

    @Autowired
    JobLauncher jobLauncher;

    @Autowired
    Job job;

    @RequestMapping("/launch")
    public String launch() throws Exception {
             ...
            jobLauncher.run(job, jobParameters);
    }

This is some part of the Batch conf:

@Configuration
@EnableBatchProcessing
@EnableScheduling
public class BatchConfiguration {

    @Autowired
    public JobBuilderFactory jobBuilderFactory;

    @Autowired
    public StepBuilderFactory stepBuilderFactory;

    @Scheduled(cron = "0/5 * * * * ?")
    @Bean
    public Job job() {
        return jobBuilderFactory.get("job")
                .incrementer(new RunIdIncrementer())
                .flow(step1())
                .end()
                .build();
    }

    @Bean
    public Step step1() {
        return stepBuilderFactory.get("step1")
                .<Person, Person> chunk(10)
                .reader(reader())
                .processor(processor())
                .writer(writer())
                .build();
    }

I have also set the property spring.batch.job.enabled=false, since i do not want the jobs run as soon as the Spring Boot App starts.

Now i can call my Rest api lauch, and the job runs, but only once. Scheduler does not work. And I could not figure it our where exactly i should define my @Scheduled Annotation..

Answer 1

I would approach it in a way, that scheduled job runs always, but it does something only when the flag is set to true:

@Component
class ScheduledJob {

    private final AtomicBoolean enabled = new AtomicBoolean(false);

    @Scheduled(fixedRate = 1000)
    void execute() {
        if (enabled.get()) {
            // run spring batch here.
        }
    }

    void toggle() {
        enabled.set(!enabled.get());
    }

}

and a controller:

@RestController
class HelloController {

    private final ScheduledJob scheduledJob;

    // constructor

    @GetMapping("/launch")
    void toggle() {
        scheduledJob.toggle();
    }

}