如何使用JPA回调?

@Entity
<b>public</b> <b>class</b> User implements Serializable {

    <b>private</b> <b>static</b> <b>final</b> Logger logger = 
            Logger.getLogger(User.<b>class</b>.getName());
        
    <b>private</b> <b>static</b> <b>final</b> <b>long</b> serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    <b>private</b> Long id;

    <b>private</b> String name;
    <b>private</b> String city;
    <b>private</b> <b>int</b> age;
    
    @PrePersist
    <b>public</b> <b>void</b> prePersist() {
        logger.info(<font>"@PrePersist callback ..."</font><font>);
    }       
    
    @PreUpdate
    <b>public</b> <b>void</b> preUpdate() {
        logger.info(</font><font>"@PreUpdate callback ..."</font><font>);
    }
    
    @PreRemove
    <b>public</b> <b>void</b> preRemove() {
        logger.info(</font><font>"@PreRemove callback ..."</font><font>);
    }
    
    @PostLoad
    <b>public</b> <b>void</b> postLoad() {
        logger.info(</font><font>"@PostLoad callback ..."</font><font>);
    }
    
    @PostPersist
    <b>public</b> <b>void</b> postPersist() {
        logger.info(</font><font>"@PostPersist callback ..."</font><font>);
    }
    
    @PostUpdate
    <b>public</b> <b>void</b> postUpdate() {
        logger.info(</font><font>"@PostUpdate callback ..."</font><font>);
    }
    
    @PostRemove
    <b>public</b> <b>void</b> postRemove() {
        logger.info(</font><font>"@PostRemove callback ..."</font><font>);
    }
</font>