/*
* Copyright (c) 2005-2016 Vincent Vandenschrick. All rights reserved.
*
* This file is part of the Jspresso framework.
*
* Jspresso is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Jspresso is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Jspresso. If not, see <http://www.gnu.org/licenses/>.
*/
package org.jspresso.framework.application.backend.persistence.hibernate;
import java.beans.PropertyDescriptor;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;
import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.collection.internal.AbstractPersistentCollection;
import org.hibernate.collection.internal.PersistentSet;
import org.hibernate.collection.spi.PersistentCollection;
import org.hibernate.proxy.HibernateProxy;
import org.hibernate.proxy.LazyInitializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.jspresso.framework.model.component.IComponent;
import org.jspresso.framework.model.entity.IEntity;
import org.jspresso.framework.util.bean.MissingPropertyException;
import org.jspresso.framework.util.bean.PropertyHelper;
import org.jspresso.framework.util.reflect.ReflectHelper;
/**
* A utility class for Hibernate.
*
* @author Vincent Vandenschrick
*/
public final class HibernateHelper {
private static final Logger LOG = LoggerFactory
.getLogger(HibernateHelper.class);
/**
* Constructs a new {@code HibernateUtils} instance.
*/
private HibernateHelper() {
// Helper constructor
}
/**
* Retrieves a component contract without initializing an entity.
*
* @param <E>
* The actual type of component.
* @param component
* the component to retrieve the contract for.
* @return the component contract.
*/
@SuppressWarnings("unchecked")
public static <E extends IComponent> Class<? extends E> getComponentContract(
E component) {
if (!Hibernate.isInitialized(component)) {
if (component instanceof HibernateProxy) {
try {
return (Class<? extends E>) Class
.forName(((HibernateProxy) component)
.getHibernateLazyInitializer().getEntityName());
} catch (ClassNotFoundException ex) {
LOG.warn(
"Can not retrieve entity class {} without initializing entity.",
((HibernateProxy) component).getHibernateLazyInitializer()
.getEntityName());
}
}
}
return (Class<? extends E>) component.getComponentContract();
}
/**
* Test Object equality potentially unwrapping Hibernate proxies.
*
* @param e1
* the 1st entity to test.
* @param e2
* the 2nd entity to test.
* @return true if they both refer to the same object reference.
*/
public static boolean objectEquals(IEntity e1, IEntity e2) {
IEntity actualE1 = e1;
IEntity actualE2 = e2;
if (actualE1 instanceof HibernateProxy && Hibernate.isInitialized(actualE1)) {
actualE1 = (IEntity) ((HibernateProxy) actualE1)
.getHibernateLazyInitializer().getImplementation();
}
if (actualE2 instanceof HibernateProxy && Hibernate.isInitialized(actualE2)) {
actualE2 = (IEntity) ((HibernateProxy) actualE2)
.getHibernateLazyInitializer().getImplementation();
}
return actualE1 == actualE2;
}
/**
* Computes the Hibernate role name of a persistent collection.
*
* @param entityContract
* the entity contract owing the collection.
* @param property
* the property name to compute the role name for.
* @return the Hibernate role name of the persistent collection.
*/
public static String getHibernateRoleName(Class<?> entityContract,
String property) {
// have to find the highest entity class declaring the collection role.
PropertyDescriptor roleDescriptor;
try {
roleDescriptor = PropertyHelper.getPropertyDescriptor(entityContract,
property);
} catch (MissingPropertyException ex) {
return null;
}
Class<?> propertyDeclaringClass = roleDescriptor.getReadMethod()
.getDeclaringClass();
Class<?> roleClass;
if (IEntity.class.isAssignableFrom(propertyDeclaringClass)) {
roleClass = propertyDeclaringClass;
} else {
roleClass = getHighestEntityClassInRole(entityContract,
propertyDeclaringClass);
}
return roleClass.getName() + "." + PropertyHelper.toJavaBeanPropertyName(property);
}
private static Class<?> getHighestEntityClassInRole(Class<?> entityContract,
Class<?> propertyDeclaringClass) {
for (Class<?> superInterface : entityContract.getInterfaces()) {
if (IEntity.class.isAssignableFrom(superInterface)
&& propertyDeclaringClass.isAssignableFrom(superInterface)) {
return getHighestEntityClassInRole(superInterface,
propertyDeclaringClass);
}
}
return entityContract;
}
/**
* Ensures that the collection held by a Persistent Set is actually a
* LinkedHashSet.
*
* @param collection
* the collection to ensure implementation of.
*/
public static void ensureInnerLinkedHashSet(Collection<?> collection) {
if (collection instanceof PersistentSet) {
try {
Set<?> innerSet = (Set<?>) ReflectHelper.getPrivateFieldValue(
PersistentSet.class, "set", collection);
if (innerSet != null && !(innerSet instanceof LinkedHashSet<?>)) {
ReflectHelper.setPrivateFieldValue(PersistentSet.class, "set",
collection, new LinkedHashSet<>(innerSet));
}
} catch (Exception ex) {
LOG.error("Failed to replace internal Hibernate set implementation");
}
}
}
/**
* Whenever the entity has dirty persistent collection, make them clean to
* workaround a "bug" with hibernate since hibernate cannot re-attach a
* "dirty" detached collection.
*
* @param collection the collection
* @param targetSession the session that is targeted to after the dirty states have been
* reset or null if none.
*/
public static void unsetCollectionHibernateSession(PersistentCollection collection, Session targetSession) {
// Whenever the entity has dirty persistent collection, make them
// clean to workaround a "bug" with hibernate since hibernate cannot
// re-attach a "dirty" detached collection.
if (collection != null) {
if (Hibernate.isInitialized(collection)) {
collection.clearDirty();
}
if (collection instanceof AbstractPersistentCollection
&& ((AbstractPersistentCollection) collection).getSession() != null
&& targetSession != ((AbstractPersistentCollection) collection).getSession()) {
// The following is to avoid to avoid Hibernate exceptions due to
// re-associating a collection that is already associated with the
// session.
collection.unsetSession(((AbstractPersistentCollection) collection).getSession());
}
}
}
/**
* Unset proxy hibernate session.
*
* @param entity the entity
* @param hibernateSession the hibernate session
*/
public static void unsetProxyHibernateSession(IEntity entity, Session hibernateSession) {
if (entity instanceof HibernateProxy) {
LazyInitializer li = ((HibernateProxy) entity)
.getHibernateLazyInitializer();
if (li.getSession() != null && li.getSession() != hibernateSession) {
li.unsetSession();
}
}
}
}