au.edu.anu.metadatastores.harvester.HarvestContentService.java Source code

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Here is the source code for au.edu.anu.metadatastores.harvester.HarvestContentService.java

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/*******************************************************************************
 * Australian National University Metadata Stores
 * Copyright (C) 2013  The Australian National University
 * 
 * This file is part of Australian National University Metadata Stores.
 * 
 * Australian National University Metadata Stores 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.metadatastores.harvester;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;

import au.edu.anu.metadatastores.datamodel.harvester.HarvestContent;
import au.edu.anu.metadatastores.datamodel.harvester.Location;

/**
 * <p>HarvestContentService<p>
 * 
 * <p>The Australian National University</p>
 * 
 * <p>Harvest Content Service, this class processes the harvesting</p>
 * 
 * @author Genevieve Turner
 *
 */
public class HarvestContentService {
    private static HarvestContentService singleton_;

    /**
     * Constructor
     */
    private HarvestContentService() {
    }

    /**
     * Retrieves the singleton class for the service
     * 
     * @return The HarvestContentService object
     */
    public static HarvestContentService getSingleton() {
        if (singleton_ == null) {
            singleton_ = new HarvestContentService();
        }
        return singleton_;
    }

    /**
     * Get the next row of harvest content to process
     * 
     * @param system The system to get the harvest content for
     * @return The harvest content record
     */
    public HarvestContent getNextHarvestContent(String system) {
        Session session = HarvesterHibernateUtil.getSessionFactory().openSession();
        try {
            Query query = session.createQuery("FROM HarvestContent WHERE system = :system ORDER BY hid");
            query.setParameter("system", system);

            HarvestContent content = (HarvestContent) query.setMaxResults(1).uniqueResult();

            return content;
        } finally {
            session.close();
        }
    }

    /**
     * Delete the harvest content row
     * 
     * @param content The harvest content row to delete
     */
    public void deleteHarvestContent(HarvestContent content) {
        Session session = HarvesterHibernateUtil.getSessionFactory().openSession();
        try {
            session.beginTransaction();

            session.delete(content);

            session.getTransaction().commit();
        } finally {
            session.close();
        }
    }

    /**
     * Get the harvest locations
     * 
     * @return The harvest locations
     */
    public List<Location> getHarvestLocations() {
        Session session = HarvesterHibernateUtil.getSessionFactory().openSession();
        try {
            @SuppressWarnings("unchecked")
            List<Location> locations = session.createQuery("FROM Location").list();
            return locations;
        } finally {
            session.close();
        }
    }
}