Lifecycle Callbacks

import jakarta.persistence.*;

/**
 * Specifies a callback method for the corresponding lifecycle event
 */
@Target({METHOD})
@Retention(RUNTIME)
public @interface PrePersist {}

@Target({METHOD})
@Retention(RUNTIME)
public @interface PostPersist {}

@Target({METHOD})
@Retention(RUNTIME)
public @interface PreUpdate {}

@Target({METHOD})
@Retention(RUNTIME)
public @interface PostUpdate {}

@Target({METHOD})
@Retention(RUNTIME)
public @interface PreRemove {}

@Target({METHOD})
@Retention(RUNTIME)
public @interface PostRemove {}

@Target({METHOD})
@Retention(RUNTIME)
public @interface PostLoad {}

/**
 * Specifies callback listener classes
 */
@Target({TYPE})
@Retention(RUNTIME)
public @interface EntityListeners {
    Class[] value();
}

/**
 * Exclude default listeners
 */
@Target({TYPE})
@Retention(RUNTIME)
public @interface ExcludeDefaultListeners {}

/**
 * Exclude superclass listeners
 */
@Target({TYPE})
@Retention(RUNTIME)
public @interface ExcludeSuperclassListeners {}

@Entity
@EntityListeners({AuditListener.class, ValidationListener.class})
public class User {
    @Id
    private Long id;
    private String name;
    private LocalDateTime createdAt;
    private LocalDateTime updatedAt;

    @PrePersist
    protected void onCreate() {
        createdAt = LocalDateTime.now();
    }

    @PreUpdate
    protected void onUpdate() {
        updatedAt = LocalDateTime.now();
    }

    @PostLoad
    protected void onLoad() {
        // Initialize transient fields
    }
}

public class AuditListener {
    @PrePersist
    public void prePersist(Object entity) {
        // Audit logging
    }

    @PostPersist
    public void postPersist(Object entity) {
        // Post-persist actions
    }
}