de.visualdependencies.data.dao.impl.AbstractGeneralDaoImpl.java Source code

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Here is the source code for de.visualdependencies.data.dao.impl.AbstractGeneralDaoImpl.java

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/*
 * visualDependencies (visualize your database)
 * Copyright (C) 2009-2010 Andre Kasper, Jan Philipp <knallisworld@googlemail.com>
 *
 * This program 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package de.visualdependencies.data.dao.impl;

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

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.hibernate.transform.DistinctRootEntityResultTransformer;
import org.springframework.beans.factory.annotation.Autowired;

import de.visualdependencies.data.dao.GeneralDao;
import de.visualdependencies.data.entity.AbstractEntity;
import de.visualdependencies.data.entity.Schema;

public abstract class AbstractGeneralDaoImpl<E extends AbstractEntity<? extends Serializable>>
        implements GeneralDao<E> {

    private final Class<E> persistentClass;

    @Autowired
    protected SessionFactory sessionFactory;

    @SuppressWarnings("unchecked")
    protected AbstractGeneralDaoImpl() {
        // Retrieve the annotated class of generic type T.
        persistentClass = (Class<E>) ((ParameterizedType) this.getClass().getGenericSuperclass())
                .getActualTypeArguments()[0];
    }

    @Override
    public E create() {
        try {
            final E instance = getPersistentClass().newInstance();
            return instance;
        } catch (final Exception e) {
            return null;
        }
    }

    protected Criteria createCriteria() {
        final Session session = sessionFactory.getCurrentSession();
        final Criteria criteria = session.createCriteria(getPersistentClass());

        // If an entity has any mapped collection with eager loading, this will avoid multiple result tuples.
        // See: https://forum.hibernate.org/viewtopic.php?f=25&t=988655
        criteria.setResultTransformer(DistinctRootEntityResultTransformer.INSTANCE);

        return criteria;
    }

    @Override
    public boolean delete(final E entity) {
        sessionFactory.getCurrentSession().delete(entity);
        return true;
    }

    @SuppressWarnings("unchecked")
    @Override
    public E findById(final Serializable id) {
        return (E) sessionFactory.getCurrentSession().load(getPersistentClass(), id);
    }

    public Class<E> getPersistentClass() {
        return persistentClass;
    }

    @Override
    public List<E> list() {
        final Criteria criteria = createCriteria();
        criteria.addOrder(Order.asc("name"));
        @SuppressWarnings("unchecked")
        final List<E> list = criteria.list();
        return list;
    }

    public List<E> list(final Schema schema) {
        @SuppressWarnings("unchecked")
        final List<E> list = createCriteria().add(Restrictions.eq("schema.id", schema.getId())).list();
        return list;
    }

    @Override
    public boolean save(final E entity) {
        sessionFactory.getCurrentSession().saveOrUpdate(entity);
        return true;
    }

}