How to cancel delete using AbstractMongoEventListener?

Question

Can I cancel delete event using onBeforeDelete method of MongoGenreCancelDeleteEventsListener? If yes then how?

@Component
public class MongoGenreCancelDeleteEventsListener extends AbstractMongoEventListener<Genre> {
    private final BookRepository bookRepository;
    @Override
    public void onBeforeDelete(BeforeDeleteEvent<Genre> event) {
        super.onBeforeDelete(event);
       // check conditions and cancel delete
    } 
}

Answer 1

I know this is an old question, but I had the same issue and I found a solution.

Basically, your code should become like this:

@Component
public class MongoGenreCancelDeleteEventsListener extends AbstractMongoEventListener<Genre> {

    private BookRepository bookRepository;

    @Override
    public void onBeforeDelete(BeforeDeleteEvent<Genre> event) {
        super.onBeforeDelete(event);
        boolean abort = false;
        //do your check and set abort to true if necessary
        if (abort) {
            throw new IllegalStateException(); //or any exception you like
        }
    } 

}

The thrown exception prevents the operation from going further and it stops there. Also, the exception gets propagated to the caller (anyway, it is wrapped inside a UndeclaredThrowableException, so this is what you should catch; make sure that the wrapped exception is indeed the one you've thrown by calling the getCause() method).

Hope it helps.