com.ikon.dao.GenericDAO.java Source code

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Here is the source code for com.ikon.dao.GenericDAO.java

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/**
 *  openkm, Open Document Management System (http://www.openkm.com)
 *  Copyright (c) 2006-2013  Paco Avila & Josep Llort
 *
 *  No bytes were intentionally harmed during the development of this application.
 *
 *  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 com.ikon.dao;

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

import org.hibernate.Hibernate;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.ikon.core.DatabaseException;

/**
 * Based on these ideas:
 *  - http://slemos.com.ar/java/2007/10/como-realizar-un-dao-sin-repetir-con-generics/
 *  - http://community.jboss.org/wiki/GenericDataAccessObjects
 * 
 * @author pavila
 */
public abstract class GenericDAO<T, ID extends Serializable> {
    private static Logger log = LoggerFactory.getLogger(GenericDAO.class);
    private Class<T> persistentClass;
    private Session session;

    @SuppressWarnings("unchecked")
    public GenericDAO() {
        ParameterizedType thisType = (ParameterizedType) getClass().getGenericSuperclass();
        this.persistentClass = (Class<T>) thisType.getActualTypeArguments()[0];
    }

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

    public void setSession(Session session) {
        this.session = session;
    }

    protected Session getSession() {
        return session;
    }

    /**
     * Create
     */
    @SuppressWarnings("unchecked")
    public ID create(T t) throws DatabaseException {
        log.debug("create({})", t);
        Session session = null;
        Transaction tx = null;

        try {
            session = HibernateUtil.getSessionFactory().openSession();
            tx = session.beginTransaction();
            ID id = (ID) session.save(t);
            HibernateUtil.commit(tx);
            log.debug("create: {}", id);
            return id;
        } catch (HibernateException e) {
            HibernateUtil.rollback(tx);
            throw new DatabaseException(e.getMessage(), e);
        } finally {
            HibernateUtil.close(session);
        }
    }

    /**
     * Update
     */
    public void update(T t) throws DatabaseException {
        log.debug("update({})", t);
        Session session = null;
        Transaction tx = null;

        try {
            session = HibernateUtil.getSessionFactory().openSession();
            tx = session.beginTransaction();
            session.update(t);
            HibernateUtil.commit(tx);
        } catch (HibernateException e) {
            HibernateUtil.rollback(tx);
            throw new DatabaseException(e.getMessage(), e);
        } finally {
            HibernateUtil.close(session);
        }

        log.debug("update: void");
    }

    /**
     * Delete
     */
    @SuppressWarnings("unchecked")
    public void delete(ID id) throws DatabaseException {
        log.debug("delete({})", id);
        Session session = null;
        Transaction tx = null;

        try {
            session = HibernateUtil.getSessionFactory().openSession();
            tx = session.beginTransaction();
            T t = (T) session.load(persistentClass, id);
            session.delete(t);
            HibernateUtil.commit(tx);
        } catch (HibernateException e) {
            HibernateUtil.rollback(tx);
            throw new DatabaseException(e.getMessage(), e);
        } finally {
            HibernateUtil.close(session);
        }

        log.debug("delete: void");
    }

    /**
     * Find by primary key
     */
    @SuppressWarnings("unchecked")
    public T findByPk(ID id) throws DatabaseException {
        log.debug("findByPk({})", id);
        Session session = null;

        try {
            session = HibernateUtil.getSessionFactory().openSession();
            T ret = (T) session.load(persistentClass, id);
            Hibernate.initialize(ret);
            log.debug("findByPk: {}", ret);
            return ret;
        } catch (HibernateException e) {
            throw new DatabaseException(e.getMessage(), e);
        } finally {
            HibernateUtil.close(session);
        }
    }

    /**
     * Find by primary key
     */
    @SuppressWarnings("unchecked")
    public List<T> findAll() throws DatabaseException {
        log.debug("findAll()");
        Session session = null;

        try {
            session = HibernateUtil.getSessionFactory().openSession();
            Query q = session.createQuery("from " + persistentClass.getName() + " x");
            List<T> ret = q.list();
            log.debug("findAll: {}", ret);
            return ret;
        } catch (HibernateException e) {
            throw new DatabaseException(e.getMessage(), e);
        } finally {
            HibernateUtil.close(session);
        }
    }
}