/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.servicelayer.common;
import java.lang.reflect.ParameterizedType;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.criterion.Restrictions;
import com.iluwatar.servicelayer.hibernate.HibernateUtil;
/**
*
* Base class for Dao implementations.
*
* @param <E>
*
*/
public abstract class DaoBaseImpl<E extends BaseEntity> implements Dao<E> {
@SuppressWarnings("unchecked")
protected Class<E> persistentClass = (Class<E>) ((ParameterizedType) getClass()
.getGenericSuperclass()).getActualTypeArguments()[0];
/*
* Making this getSessionFactory() instead of getSession() so that it is the responsibility
* of the caller to open as well as close the session (prevents potential resource leak).
*/
protected SessionFactory getSessionFactory() {
return HibernateUtil.getSessionFactory();
}
@Override
public E find(Long id) {
Session session = getSessionFactory().openSession();
Transaction tx = null;
E result = null;
try {
tx = session.beginTransaction();
Criteria criteria = session.createCriteria(persistentClass);
criteria.add(Restrictions.idEq(id));
result = (E) criteria.uniqueResult();
tx.commit();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
return result;
}
@Override
public void persist(E entity) {
Session session = getSessionFactory().openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
session.persist(entity);
tx.commit();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
}
@Override
public E merge(E entity) {
Session session = getSessionFactory().openSession();
Transaction tx = null;
E result = null;
try {
tx = session.beginTransaction();
result = (E) session.merge(entity);
tx.commit();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
return result;
}
@Override
public void delete(E entity) {
Session session = getSessionFactory().openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
session.delete(entity);
tx.commit();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
}
@Override
public List<E> findAll() {
Session session = getSessionFactory().openSession();
Transaction tx = null;
List<E> result = null;
try {
tx = session.beginTransaction();
Criteria criteria = session.createCriteria(persistentClass);
result = criteria.list();
} catch (Exception e) {
if (tx != null) {
tx.rollback();
}
throw e;
} finally {
session.close();
}
return result;
}
}