org.glite.security.voms.admin.persistence.dao.hibernate.GenericHibernateDAO.java Source code

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Here is the source code for org.glite.security.voms.admin.persistence.dao.hibernate.GenericHibernateDAO.java

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/**
 * Copyright (c) Istituto Nazionale di Fisica Nucleare (INFN). 2006-2016
 *
 * 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.glite.security.voms.admin.persistence.dao.hibernate;

import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.util.List;

import org.glite.security.voms.admin.persistence.HibernateFactory;
import org.glite.security.voms.admin.persistence.dao.generic.GenericDAO;
import org.hibernate.Criteria;
import org.hibernate.LockMode;
import org.hibernate.Session;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Example;

/**
 * Implements the generic CRUD data access operations using Hibernate APIs.
 * <p>
 * To write a DAO, subclass and parameterize this class with your persistent
 * class. Of course, assuming that you have a traditional 1:1 appraoch for
 * Entity:DAO design.
 * <p>
 * You have to inject a current Hibernate <tt>Session</tt> to use a DAO.
 * Otherwise, this generic implementation will use
 * <tt>HibernateUtil.getSessionFactory()</tt> to obtain the curren
 * <tt>Session</tt>.
 * 
 * @see HibernateDAOFactory
 * 
 * @author Christian Bauer
 */
public abstract class GenericHibernateDAO<T, ID extends Serializable> implements GenericDAO<T, ID> {

    private Class<T> persistentClass;
    private Session session;

    @SuppressWarnings("unchecked")
    public GenericHibernateDAO() {

        this.persistentClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass())
                .getActualTypeArguments()[0];
        HibernateFactory.beginTransaction();
    }

    public void setSession(Session s) {

        this.session = s;
    }

    protected Session getSession() {

        if (session != null)
            return session;

        return HibernateFactory.getSession();

    }

    public Class<T> getPersistentClass() {

        return persistentClass;
    }

    @SuppressWarnings("unchecked")
    public T findById(ID id, boolean lock) {

        T entity;
        if (lock)
            entity = (T) getSession().load(getPersistentClass(), id, LockMode.UPGRADE);
        else
            entity = (T) getSession().load(getPersistentClass(), id);

        return entity;
    }

    public List<T> findAll() {

        return findByCriteria();
    }

    @SuppressWarnings("unchecked")
    public List<T> findByExample(T exampleInstance, String... excludeProperty) {

        Criteria crit = getSession().createCriteria(getPersistentClass());
        Example example = Example.create(exampleInstance);
        for (String exclude : excludeProperty) {
            example.excludeProperty(exclude);
        }
        crit.add(example);
        return crit.list();
    }

    public T makePersistent(T entity) {

        getSession().saveOrUpdate(entity);
        return entity;
    }

    public void makeTransient(T entity) {

        getSession().delete(entity);
    }

    public void flush() {

        getSession().flush();
    }

    public void clear() {

        getSession().clear();
    }

    /**
     * Use this inside subclasses as a convenience method.
     */
    @SuppressWarnings("unchecked")
    protected List<T> findByCriteria(Criterion... criterion) {

        Criteria crit = getSession().createCriteria(getPersistentClass());
        for (Criterion c : criterion) {
            crit.add(c);
        }
        return crit.list();
    }

    @SuppressWarnings("unchecked")
    protected T findByCriteriaUniqueResult(Criterion... criterion) {

        Criteria crit = getSession().createCriteria(getPersistentClass());
        for (Criterion c : criterion) {
            crit.add(c);
        }

        return (T) crit.uniqueResult();
    }

    protected Criteria createCriteria(Criterion... criterion) {

        Criteria crit = getSession().createCriteria(getPersistentClass());
        for (Criterion c : criterion) {
            crit.add(c);
        }

        return crit;
    }

}