Async

For Spring async to work, we have to @EnableAsync.

@SpringBootApplication  
@EnableAsync  
public class Application {  
  public static void main(String[] args) {  
    SpringApplication.run(Application.class, args);  
  }  
}

And then we can use @Async to denote method that is async to run in a separate thread.

The method that is async needs to have a Future<> return or void

@Slf4j  
@Service  
public class TaskService {  
  @Async  
  public Future<String> getResult() {  
    return CompletableFuture.completedFuture("hi");  
  }  
}

@RestController
public class MyController {
	@RequestMapping(value = "/asynctest", method = RequestMethod.GET)  
	public String getValue() throws ExecutionException, InterruptedException {  
	  return taskService.getResult().get();  
	}
}