/*******************************************************************************
* Australian National University Data Commons
* Copyright (C) 2013 The Australian National University
*
* This file is part of Australian National University Data Commons.
*
* Australian National University Data Commons is free software: you
* can redistribute it and/or modify it under the terms of the GNU
* General Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later
* version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
package au.edu.anu.datacommons.data.db.dao;
import java.io.Serializable;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityTransaction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import au.edu.anu.datacommons.data.db.PersistenceManager;
/**
* GenericDAOImpl
*
* Australian National University Data Commons
*
* Generic Data Access Object implementation
*
* JUnit Coverage:
* None
*
* <pre>
* Version Date Developer Description
* 0.1 03/05/2012 Genevieve Turner (GT) Initial
* 0.2 09/05/2012 Genevieve Turner (GT) Added constructor class
* 0.3 15/05/2012 Genevieve Turner (GT) Fixed an issue with 'detached entity passed to persist'
* 0.4 29/06/2012 Genevieve Turner (GT) Updated to retrieve the object prior to delete
* 0.5 23/08/2012 Genevieve Turner (GT) Removed log statement after entity manager close
* </pre>
*
* @param <T> The object type to implement
* @param <PK> The primary key type to implement
*/
public class GenericDAOImpl<T, PK extends Serializable> implements GenericDAO<T, PK> {
static final Logger LOGGER = LoggerFactory.getLogger(GenericDAOImpl.class);
private Class<T> type_;
/**
* Constructor
*
* <pre>
* Version Date Developer Description
* 0.2 09/05/2012 Genevieve Turner (GT) Included so the actual type can be referenced
* </pre>
*
* @param type The class type to retrive/set objects
*/
public GenericDAOImpl(Class<T> type) {
// Attempting to have a default constructor that uses ParameterizedType causes errors
// So we need to have a constructor that sets the class type
this.type_ = type;
}
/**
* create
*
* Creates the object in the database
*
* <pre>
* Version Date Developer Description
* 0.1 03/05/2012 Genevieve Turner (GT) Initial
* </pre>
*
* @param t The object to create in the database
* @return
*/
public T create(T o) {
EntityManager entityManager = PersistenceManager.getEntityManagerFactory().createEntityManager();
EntityTransaction entityTransaction = entityManager.getTransaction();
try {
entityTransaction.begin();
entityManager.persist(o);
entityTransaction.commit();
}
finally {
entityManager.close();
}
return o;
}
/**
* getSingleById
*
* Retrieves the object by the primary key
*
* <pre>
* Version Date Developer Description
* 0.1 03/05/2012 Genevieve Turner (GT) Initial
* 0.5 23/08/2012 Genevieve Turner (GT) Removed log statement after entity manager close
* </pre>
*
* @param id The primary key of the object to retrieve
* @return
*/
public T getSingleById(PK id) {
EntityManager entityManager = PersistenceManager.getEntityManagerFactory().createEntityManager();
T object = null;
try {
object = (T) entityManager.find(type_, id);
}
finally {
entityManager.close();
}
return object;
}
/**
* getAll
*
* Retrieves all objects of the approriate type
*
* <pre>
* Version Date Developer Description
* 0.1 03/05/2012 Genevieve Turner (GT) Initial
* </pre>
*
* @return A list of objects of the appropriate type
*/
public List<T> getAll() {
EntityManager entityManager = PersistenceManager.getEntityManagerFactory().createEntityManager();
List<T> objects = null;
try {
objects = entityManager.createQuery("from " + type_.getName()).getResultList();
}
finally {
entityManager.close();
}
return objects;
}
/**
* update
*
* Updates the object in the database
*
* <pre>
* Version Date Developer Description
* 0.1 03/05/2012 Genevieve Turner (GT) Initial
* 0.3 15/05/2012 Genevieve Turner (GT) Fixed an issue with 'detached entity passed to persist'
* </pre>
*
* @param t The object to update
* @return
*/
public T update(T o) {
EntityManager entityManager = PersistenceManager.getEntityManagerFactory().createEntityManager();
EntityTransaction entityTransaction = entityManager.getTransaction();
try {
entityTransaction.begin();
o = entityManager.merge(o);
entityTransaction.commit();
}
finally {
entityManager.close();
}
return o;
}
/**
* delete
*
* Removes objects from the database
*
* <pre>
* Version Date Developer Description
* 0.1 03/05/2012 Genevieve Turner (GT) Initial
* 0.4 29/06/2012 Genevieve Turner (GT) Updated to retrieve the object prior to delete
* </pre>
*
* @param t The object to delete
*/
public void delete (PK id) {
EntityManager entityManager = PersistenceManager.getEntityManagerFactory().createEntityManager();
EntityTransaction entityTransaction = entityManager.getTransaction();
try {
entityTransaction.begin();
entityManager.remove(entityManager.getReference(type_, id));
entityTransaction.commit();
}
finally {
entityManager.close();
}
}
}