Declaring Hibernate event listeners in a JPA environment

Question

Hy guys,

I am working on a project developed in Java EE 5 environment. I want to know how I can declare a Hibernate event listener so that I can be informed when CRUD op

Answer 1

I assume you are using annotations? If so, you can use the @EntityListeners annotation to do that, like so:

@MappedSuperclass
@EntityListeners(AbstractEntityListener.class)
public abstract class AbstractEntity {
    ...
}

Your entity listener class could look like this:

public class AbstractEntityListener {

    /**
     * Set creation and lastUpdated date of the entity.
     * 
     * @param entity {@link AbstractEntity}
     */
    @PrePersist
    @PreUpdate
    public void setDate(final AbstractEntity entity) {
        final Date now = new Date();
        entity.setModified(now);
    }

}

There are different annotations available to catch different events, like @PrePersist, @PreUpdate, @PostLoad, etc.