/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.orm.jpa.support;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import org.springframework.dao.support.DaoSupport;
import org.springframework.orm.jpa.JpaTemplate;
/**
* Convenient super class for JPA data access objects. Intended for
* JpaTemplate usage. Alternatively, JPA-based DAOs can be coded
* against the plain JPA EntityManagerFactory/EntityManager API.
*
* <p>Requires an EntityManagerFactory or EntityManager to be set,
* providing a JpaTemplate based on it to subclasses. Can alternatively
* be initialized directly via a JpaTemplate, to reuse the latter's
* settings such as the EntityManagerFactory, JpaDialect, flush mode, etc.
*
* <p>This class will create its own JpaTemplate if an EntityManagerFactory
* or EntityManager reference is passed in. A custom JpaTemplate instance
* can be used through overriding <code>createJpaTemplate</code>.
*
* @author Juergen Hoeller
* @since 2.0
* @see #setEntityManagerFactory
* @see #setEntityManager
* @see #createJpaTemplate
* @see #setJpaTemplate
* @see org.springframework.orm.jpa.JpaTemplate
*/
public abstract class JpaDaoSupport extends DaoSupport {
private JpaTemplate jpaTemplate;
/**
* Set the JPA EntityManagerFactory to be used by this DAO.
* Will automatically create a JpaTemplate for the given EntityManagerFactory.
* @see #createJpaTemplate
* @see #setJpaTemplate
*/
public final void setEntityManagerFactory(EntityManagerFactory entityManagerFactory) {
if (this.jpaTemplate == null || entityManagerFactory != this.jpaTemplate.getEntityManagerFactory()) {
this.jpaTemplate = createJpaTemplate(entityManagerFactory);
}
}
/**
* Create a JpaTemplate for the given EntityManagerFactory.
* Only invoked if populating the DAO with a EntityManagerFactory reference!
* <p>Can be overridden in subclasses to provide a JpaTemplate instance
* with different configuration, or a custom JpaTemplate subclass.
* @param entityManagerFactory the JPA EntityManagerFactory to create a JpaTemplate for
* @return the new JpaTemplate instance
* @see #setEntityManagerFactory
*/
protected JpaTemplate createJpaTemplate(EntityManagerFactory entityManagerFactory) {
return new JpaTemplate(entityManagerFactory);
}
/**
* Set the JPA EntityManager to be used by this DAO.
* Will automatically create a JpaTemplate for the given EntityManager.
* @see #createJpaTemplate
* @see #setJpaTemplate
*/
public final void setEntityManager(EntityManager entityManager) {
this.jpaTemplate = createJpaTemplate(entityManager);
}
/**
* Create a JpaTemplate for the given EntityManager.
* Only invoked if populating the DAO with a EntityManager reference!
* <p>Can be overridden in subclasses to provide a JpaTemplate instance
* with different configuration, or a custom JpaTemplate subclass.
* @param entityManager the JPA EntityManager to create a JpaTemplate for
* @return the new JpaTemplate instance
* @see #setEntityManagerFactory
*/
protected JpaTemplate createJpaTemplate(EntityManager entityManager) {
return new JpaTemplate(entityManager);
}
/**
* Set the JpaTemplate for this DAO explicitly,
* as an alternative to specifying a EntityManagerFactory.
* @see #setEntityManagerFactory
*/
public final void setJpaTemplate(JpaTemplate jpaTemplate) {
this.jpaTemplate = jpaTemplate;
}
/**
* Return the JpaTemplate for this DAO, pre-initialized
* with the EntityManagerFactory or set explicitly.
*/
public final JpaTemplate getJpaTemplate() {
return jpaTemplate;
}
@Override
protected final void checkDaoConfig() {
if (this.jpaTemplate == null) {
throw new IllegalArgumentException("entityManagerFactory or jpaTemplate is required");
}
}
}