Submitting a background task from spring mvc app

Using thread ID is too low level and brittle. If you decided to use @Async annotation (good choice) you can use Future<T> to control the task execution. Basically your method should return a Future<T> instead of void:

@Asyncpublic Future<Work> work() //...

Now you can cancel() that Future or wait for it to complete:

@ResponseBody@RequestMapping("/job/start")public String start() {    Future<Work> future = asyncWorker.work();    //store future somewhere    return "start";}@ResponseBody@RequestMapping("/job/stop")public String stop() {    future.cancel();    return "stop";}

The tricky part is to store the returned future object somehow so it is available for subsequent requests. Of course you cannot use a field or ThreadLocal. You can put in session, note however that Future is not serializable and won't work across clusters.

Since @Async is typically backed by thread pool, chances are your tasks didn't even started. Cancelling will simply remove it from the pool. If the task is already running, you can the isInterrupted() thread flag or handle InterruptedException to discover cancel() call.