Lifecycle Annotations

Question 1

What

Answer 1

Lifecycle annotations allow you to hook into an entity’s lifecycle and execute custom logic at specific lifecycle events. These annotations are methods in the entity class that the persistence provider automatically calls.

Question 2

@PrePersist

Answer 2

Called before an entity is persisted.
Useful for initializing or validating fields before saving.

Question 3

@PostPersist

Answer 3

Called after an entity has been persisted.
Useful for logging or triggering additional processes.

Question 4

@PreUpdate

Answer 4

Called before an entity is updated.
Useful for setting fields like lastModified.

Question 5

@PostUpdate

Answer 5

Called after an entity is updated

Question 6

@PreRemove

Answer 6

Called before an entity is removed.
Useful for cleanup tasks.

Question 7

@PostRemove

Answer 7

Called after an entity is removed.

Question 8

@PostLoad

Answer 8

Called after an entity is loaded from the database.
Useful for initializing transient fields.

Question 9

Example

Answer 9

@Entity
public class Order {
@Id
@GeneratedValue
private Long id;

@OneToMany(mappedBy = "order", cascade = CascadeType.ALL, orphanRemoval = true)
private List<OrderItem> items = new ArrayList<>();

@PrePersist
public void prePersist() {
    System.out.println("Preparing to persist order: " + this);
}

@PostPersist
public void postPersist() {
    System.out.println("Order persisted: " + this);
} }