ThreadPoolTaskScheduler doesn't works asynchronously.

[Itamar Levi]

Hello,

I am using Spring-BOOT
I am trying to execute some task in the same time.

1. I defined a scheduler
2. set pool-size to 10.
3. schedule some tasks (for loop ) with crone expression for every 1 second.

I expected the scheduler to execute 10 task with different threads asynchronously.
But  it executes each time with only one thread.

@Configuration
public class JobScheduleConfig {
	//TODO  set configuration
	public static final int PROPERTY_NAME_OSS_SCHEDULER_POOL_SIZE = 10;
	
	public JobScheduleConfig() {
	}

	@Bean
	public ThreadPoolTaskScheduler jobScheduler(){
		ThreadPoolTaskScheduler jobScheduler = new ThreadPoolTaskScheduler();
		jobScheduler.setPoolSize(PROPERTY_NAME_OSS_SCHEDULER_POOL_SIZE);
		return jobScheduler;
	}
}

@Component
public class JobSchedulerInitializer {

	@Autowired
	private ThreadPoolTaskScheduler jobScheduler;
		
	public JobSchedulerInitializer() {
	}
	
	@PostConstruct
	public void init() throws CDRProcessManagerException{
		checkScheduket(jobScheduler);
	}
	
	public static void checkScheduket(ThreadPoolTaskScheduler jobScheduler){
		
		jobScheduler.schedule(new Runnable() {
			@Override
			public void run() {
				System.out.println(Thread.currentThread().getName());
				
				for(int i=0; i< 40; i++){
					System.out.println(Thread.currentThread().getName());
					try {
						Thread.sleep(10000);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				
				}
				
			}
		}, new CronTrigger("0/01 * * * * *"));
	}
}

the output is :
jobScheduler-1
jobScheduler-1
jobScheduler-1
jobScheduler-1
jobScheduler-1
jobScheduler-1

It is like using only one thread, but it has 10 threads in the pool.


i expected to be asyncronically :
jobScheduler-1
jobScheduler-2
jobScheduler-3
jobScheduler-4
jobScheduler-1
jobScheduler-3
jobScheduler-1
...

What is wrong?

Thanks
Itamar.

[Paul Clapham]

Perhaps I'm misunderstanding your code, but it seems to me that you are only scheduling one task, and therefore the pool only needs to use one thread for that.

You also have some code which prints the thread name 41 times, and I have no idea why you're doing that, but you should expect to see the thread name printed 41 times. Which is what you are seeing.