info.archinnov.achilles.type.interceptor

Interface Interceptor<T>

Type Parameters:

T - : type of entity to which this interceptor applies

public interface Interceptor<T>

Interface to define an entity interceptor.
The "boolean acceptEntity(Class<?> entityClass)" method decides on which entity this interceptor should trigger

The "List<Event> interceptOnEvents()" method returns a list of Event in the entity lifecycle to be intercepted.

The "void onEvent(T entity, Event event)" method is called upon interception. This is where interception logic takes place. A raw instance of the entity is injected as parameter for this method as well as the current Event. The raw instance state may be modified according to some functional logic

Please note that during interception, the interceptor should NOT remove the primary key. A verification is performed by Achilles after entity interception to guarantee that the primary key and/or all its components are not null.

It is still possible to modify the primary key for POST_LOAD/POST_INSERT/POST_DELETE events, although it is strongly discouraged to do so

Below is an example of an interceptor on the User entity to set the biography field with "TO DO" when it is not set. This interception occurs before insert only operations

 public class UserInterceptor extends Interceptor<User>
 {
 public boolean acceptEntity(Class<?> entityClass) {
 return entityClass.equals(User.class);
 }

 public void onEvent(User entity, Event event) {
 if(event == Event.PRE_INSERT && entity.getBiography() == null) {
 entity.setBiography("TO DO");
 }
 }

 public List<Event> interceptOnEvents() {
 return Arrays.asList(PRE_INSERT,PRE_UPDATE);
 }
 }
 

See Also:

Interceptors

Method Summary

Modifier and Type	Method and Description
boolean	acceptEntity(Class<?> entityClass)
List<Event>	interceptOnEvents()
void	onEvent(T entity, Event event)

Method Detail

acceptEntity

boolean acceptEntity(Class<?> entityClass)

onEvent

void onEvent(T entity,
             Event event)

interceptOnEvents

List<Event> interceptOnEvents()