Spring MVC how to get progress of running async task

Question

I would like to start an asynchronous task from within controller like in following code sniplet from Spring docs.

import org.springframework.core.task.Tas         


        

Answer 1

Have you looked at the @Async annotation in the Spring reference doc?

First, create a bean for your asynchronous task:

@Service
public class AsyncServiceBean implements ServiceBean {

    private AtomicInteger cn;

    @Async
    public void doSomething() { 
        // triggers the async task, which updates the cn status accordingly
    }

    public Integer getCn() {
        return cn.get();
    }
}

Next, call it from the controller:

@Controller
public class YourController {

    private final ServiceBean bean;

    @Autowired
    YourController(ServiceBean bean) {
        this.bean = bean;
    }

    @RequestMapping(value = "/trigger")
    void triggerAsyncJob() {
        bean.doSomething();
    }

    @RequestMapping(value = "/status")
    @ResponseBody
    Map fetchStatus() {
        return Collections.singletonMap("cn", bean.getCn());
    }        
}

Remember to configure an executor accordingly, e.g.