CODEWITHSUNDEEP
javaentity-frameworkjpa
brightpants
brightpants

Reputation: 525

JPA Entity Event Listener

I have an entity called recInfo, which contains a few info about creation and modification of entries in a few entities all together.

At this moment, the implementation is done with a setter, so every time I want to add a entry in one of these entities I have to create a new recInfo and set it to the recInfo field of my entity.

I was thinking about adding a listener to this few entities that, every time someone created a new one or modified it saved the timestamp, the user who created it (with sessionContext.getCallerPrincipal().toString();

I've looked in the documentation, but I found it quite hard to understand how to apply the listeners there to a change in an entity!

Upvotes: 0

Views: 1325

Answers (1)

ben_wea
ben_wea

Reputation: 141

JPA callbacks are used for this purpose.

public class EntityListener {

    @PrePersist
    @PreUpdate
    public void setRecInfo(Entity entity) {
        RecInfo recInfo = new RecInfo();
        // TODO set recInfo fields
        entity.setRecInfo(recInfo);
    }

}

@Entity
@EntityListeners (value = {EntityListener.class})
public class Entity {

    private RecInfo recInfo;

    public RecInfo getRecInfo() { return recInfo };

    public void setRecInfo(RecInfo recInfo) { this.recInfo = recInfo };

}

Upvotes: 2

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