I have a Java Spring Boot application which has a Scheduler which calls a async task from a Service The task takes a few minutes (usually 3-5mins) to complete.
The same async method from the Service can also be called trough a UI Application, by calling the API from the Spring Boot Controller.
Code:
Scheduler
@Component
public class ScheduledTasks {
@Autowired
private MyService myService;
@Scheduled(cron = "0 0 */1 * * ?")
public void scheduleAsyncTask() {
myService.doAsync();
}
}
Service
@Service
public class MyService {
@Async("threadTaskExecutor")
public void doAsync() {
//Do Stuff
}
}
Controller
@CrossOrigin
@RestController
@RequestMapping("/mysrv")
public class MyController {
@Autowired
private MyService myService;
@CrossOrigin
@RequestMapping(value = "/", method = RequestMethod.POST)
public void postAsyncUpdate() {
myService.doAsync();
}
}
The scheduler runs the async task every hour, but a user can also run it manually from the UI.
But, I do not want the async method to run again if it is already in the middle of execution.
In order to do that, I have created a table in DB which contains a flag which goes on when the method is running and then it is turned off after the method completes.
Something like this in my service class:
@Autowired
private MyDbRepo myDbRepo;
@Async("threadTaskExecutor")
public void doAsync() {
if (!myDbRepo.isRunning()) {
myDbRepo.setIsRunning(true);
//Do Stuff
myDbRepo.setIsRunning(false);
} else {
LOG.info("The Async task is already running");
}
}
Now, the problem is that the flag sometimes gets stuck due to various reasons (app restarting, some other application error etc.)
So, I want to reset the flag in DB each time the spring boot application is deployed and whenever is restarts.
How can I do that? Is there some way to run a method just after the Spring Boot Application starts, from where I can call a method from my Repo to un set the flags in the database?
Check for the @PostConstruct for e.g here https://www.baeldung.com/running-setup-logic-on-startup-in-spring
import jakarta.annotation.PostConstruct;
import org.springframework.stereotype.Component;
@Component
public class ExampleBean {
// 1. The constructor is called first.
public ExampleBean() {
System.out.println("STEP 1: Bean constructor has been called.");
}
// 2. This method runs AFTER the constructor and dependency injection are complete.
@PostConstruct
public void init() {
System.out.println("STEP 2: The @PostConstruct init() method has been called.");
}
}