/*
* JBoss, the OpenSource EJB server
*
* Distributable under LGPL license.
* See terms of license at gnu.org.
*/
package org.hibernate.ejb.event;
import java.lang.annotation.Annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.Entity;
import javax.persistence.EntityListeners;
import javax.persistence.ExcludeDefaultListeners;
import javax.persistence.ExcludeSuperclassListeners;
import javax.persistence.MappedSuperclass;
import javax.persistence.PersistenceException;
import org.hibernate.reflection.ReflectionManager;
import org.hibernate.reflection.XClass;
import org.hibernate.reflection.XMethod;
/**
* @author <a href="mailto:kabir.khan@jboss.org">Kabir Khan</a>
* @version $Revision: 10552 $
*/
public final class CallbackResolver {
private static boolean useAnnotationAnnotatedByListener;
static {
//check whether reading annotations of annotations is useful or not
useAnnotationAnnotatedByListener = false;
Target target = (Target) EntityListeners.class.getAnnotation( Target.class );
if ( target != null ) {
for ( ElementType type : target.value() ) {
if ( type.equals( ElementType.ANNOTATION_TYPE ) ) useAnnotationAnnotatedByListener = true;
}
}
}
private CallbackResolver() {
}
public static Callback[] resolveCallback(XClass beanClass, Class annotation, ReflectionManager reflectionManager) {
List<Callback> callbacks = new ArrayList<Callback>();
List<String> callbacksMethodNames = new ArrayList<String>(); //used to track overriden methods
List<Class> orderedListeners = new ArrayList<Class>();
XClass currentClazz = beanClass;
boolean stopListeners = false;
boolean stopDefaultListeners = false;
do {
Callback callback = null;
List<XMethod> methods = currentClazz.getDeclaredMethods();
final int size = methods.size();
for ( int i = 0; i < size ; i++ ) {
final XMethod xMethod = methods.get( i );
if ( xMethod.isAnnotationPresent( annotation ) ) {
Method method = reflectionManager.toMethod( xMethod );
final String methodName = method.getName();
if ( ! callbacksMethodNames.contains( methodName ) ) {
//overriden method, remove the superclass overriden method
if ( callback == null ) {
callback = new BeanCallback( method );
Class returnType = method.getReturnType();
Class[] args = method.getParameterTypes();
if ( returnType != Void.TYPE || args.length != 0 ) {
throw new RuntimeException(
"Callback methods annotated on the bean class must return void and take no arguments: " + annotation
.getName() + " - " + xMethod
);
}
if ( ! method.isAccessible() ) {
method.setAccessible( true );
}
callbacks.add( 0, callback ); //superclass first
callbacksMethodNames.add( 0, methodName );
}
else {
throw new PersistenceException(
"You can only annotate one callback method with "
+ annotation.getName() + " in bean class: " + beanClass.getName()
);
}
}
}
}
if ( !stopListeners ) {
getListeners( currentClazz, orderedListeners );
stopListeners = currentClazz.isAnnotationPresent( ExcludeSuperclassListeners.class );
stopDefaultListeners = currentClazz.isAnnotationPresent( ExcludeDefaultListeners.class );
}
do {
currentClazz = currentClazz.getSuperclass();
}
while ( currentClazz != null
&& ! ( currentClazz.isAnnotationPresent( Entity.class )
|| currentClazz.isAnnotationPresent( MappedSuperclass.class ) )
);
}
while ( currentClazz != null );
//handle default listeners
if ( ! stopDefaultListeners ) {
List<Class> defaultListeners = (List<Class>) reflectionManager.getDefaults().get( EntityListeners.class );
if ( defaultListeners != null ) {
int defaultListenerSize = defaultListeners.size();
for ( int i = defaultListenerSize - 1; i >= 0 ; i-- ) {
orderedListeners.add( defaultListeners.get( i ) );
}
}
}
for ( Class listener : orderedListeners ) {
Callback callback = null;
if ( listener != null ) {
XClass xListener = reflectionManager.toXClass( listener );
callbacksMethodNames = new ArrayList<String>();
do {
List<XMethod> methods = xListener.getDeclaredMethods();
final int size = methods.size();
for ( int i = 0; i < size ; i++ ) {
final XMethod xMethod = methods.get( i );
if ( xMethod.isAnnotationPresent( annotation ) ) {
final Method method = reflectionManager.toMethod( xMethod );
final String methodName = method.getName();
if ( ! callbacksMethodNames.contains( methodName ) ) {
//overriden method, remove the superclass overriden method
if ( callback == null ) {
try {
callback = new ListenerCallback( method, listener.newInstance() );
}
catch (IllegalAccessException e) {
throw new PersistenceException(
"Unable to create instance of " + listener.getName()
+ " as a listener of beanClass", e
);
}
catch (InstantiationException e) {
throw new PersistenceException(
"Unable to create instance of " + listener.getName()
+ " as a listener of beanClass", e
);
}
Class returnType = method.getReturnType();
Class[] args = method.getParameterTypes();
if ( returnType != Void.TYPE || args.length != 1 ) {
throw new PersistenceException(
"Callback methods annotated in a listener bean class must return void and take one argument: " + annotation
.getName() + " - " + method
);
}
if ( ! method.isAccessible() ) {
method.setAccessible( true );
}
callbacks.add( 0, callback ); // listeners first
}
else {
throw new PersistenceException(
"You can only annotate one callback method with "
+ annotation.getName() + " in bean class: " + beanClass.getName() + " and callback listener: "
+ listener.getName()
);
}
}
}
}
xListener = null; //xListener.getSuperclass();
}
while ( xListener != null );
}
}
return callbacks.toArray( new Callback[ callbacks.size() ] );
}
private static void getListeners(XClass currentClazz, List<Class> orderedListeners) {
EntityListeners entityListeners = (EntityListeners) currentClazz.getAnnotation( EntityListeners.class );
if ( entityListeners != null ) {
Class[] classes = entityListeners.value();
int size = classes.length;
for ( int index = size - 1; index >= 0 ; index-- ) {
orderedListeners.add( classes[index] );
}
}
if ( useAnnotationAnnotatedByListener ) {
Annotation[] annotations = currentClazz.getAnnotations();
for ( Annotation annot : annotations ) {
entityListeners = annot.getClass().getAnnotation( EntityListeners.class );
if ( entityListeners != null ) {
Class[] classes = entityListeners.value();
int size = classes.length;
for ( int index = size - 1; index >= 0 ; index-- ) {
orderedListeners.add( classes[index] );
}
}
}
}
}
}