@EntityListeners in your entity class

Sat Mar 20, 2010 11:02 am

@EntityListeners is used for to do action for specific actions on entity .

Listener class :

Code:: import javax.persistence.PostLoad; import javax.persistence.PostPersist; import javax.persistence.PostUpdate; import codemiles.test.jpa.Comment; public class ListenerExample { @PostLoad @PostPersist @PostUpdate public void actionFunction(Comment comment) { // When loading the object . System.out.println("Post load action "); // When persisting the object . System.out.println("Post persist action "); //When updating the values of the object System.out.println("Post update action "); } }

Entity class :

Code:: import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.EntityListeners; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.SequenceGenerator; import javax.persistence.Table; import codemiles.test.jpa.listener.ListenerExample; @EntityListeners({ListenerExample.class}) @Entity @Table(name="COMMENT") @SequenceGenerator(sequenceName="COMMENT_SEQ",name="COMMENT_SEQ_GEN") public class Comment { private long id; private String content; private Topic topic; public void setId(long id) { this.id = id; } @Id @GeneratedValue(generator="COMMENT_SEQ_GEN",strategy=GenerationType.SEQUENCE) public long getId() { return id; } @Column(name="CONTENT") public void setContent(String content) { this.content = content; } public String getContent() { return content; } @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "TOPIC_ID", nullable = false) public void setTopic(Topic topic) { this.topic = topic; } public Topic getTopic() { return topic; } }