Entity listener not called

Question

I have the following entity and associated listener

@Entity
@EntityListeners(InjuryListener::class)
class Injury(val description: String,
             @Id @GeneratedValue(strategy = GenerationType.SEQUENCE) val id: Long = 0)

@Singleton
class InjuryListener : PreDeleteEventListener {
    @PreRemove
    fun preRemove(injury: Injury) {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
    }

    override fun onPreDelete(event: PreDeleteEvent?): Boolean {
        val injury = event?.entity as Injury
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
    }
}

Yet when I delete an Injury neither of the the methods on my InjuryListener is called. Any clue about why that is?

Answer 1

As Ilya Dyoshin wrote @EntityListener and @PreRemove are not used in Micronaut Data. But you can solve it by AOP technique.

At first create your own interceptor with a pre-delete logic that you need:

@Singleton
class InjuryPreDeleteInterceptor : MethodInterceptor<Injury, Boolean> {
    override fun intercept(context: MethodInvocationContext<Injury, Boolean>): Boolean {
        val injury = context.parameterValues[0] as Injury
        if (injury.someFlag) {
            // do not delete
        } else {
            // delete
            context.proceed()
        }
        return true
    }
}

Then create annotation that will trigger the InjuryPreDeleteInterceptor:

@MustBeDocumented
@Retention(RUNTIME)
@Target(AnnotationTarget.FUNCTION)
@Around
@Type(InjuryPreDeleteInterceptor::class)
annotation class VisitInjuryDelete

And add delete() method signature annotated by previously created @VisitInjuryDelete annotation into the InjuryRepository interface:

@VisitInjuryDelete
override fun delete(Injury entity)

You can find more info about AOP in Micronaut here: https://docs.micronaut.io/latest/guide/aop.html