net.nineapps.hystqio.controller.HibernateLinkDAO.java Source code

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Here is the source code for net.nineapps.hystqio.controller.HibernateLinkDAO.java

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/*
Copyright (C) 2010 Viral Patel    
Copyright (C) 2011 9Apps.net
    
This file is part of hystqio.
    
hystqio 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.
    
hystqio 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 hystqio. If not, see <http://www.gnu.org/licenses/>.
*/

package net.nineapps.hystqio.controller;

import java.sql.Date;

import net.nineapps.hystqio.model.Link;
import net.nineapps.hystqio.util.HibernateUtil;
import net.nineapps.hystqio.util.HystqioUtils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.Query;
import org.hibernate.classic.Session;

/**
 * Struts controller which uses Hibernate to persist
 * the links in a relational database.
 *
 */
public class HibernateLinkDAO extends HibernateUtil implements LinkDAO {

    private static Log log = LogFactory.getLog(HibernateLinkDAO.class);

    public Link get(String shortCode) {

        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
        session.beginTransaction();

        Query query = session.createQuery("from Link where shortcode = :shortcode");
        query.setString("shortcode", shortCode);
        Link link = (Link) query.uniqueResult();
        if (null != link) {
            link.setClicks(link.getClicks());
            session.save(link);
        }
        session.getTransaction().commit();

        return link;

    }

    public Link add(Link link) {

        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
        session.beginTransaction();

        Query query = session.createQuery("from Link where url = :url");
        query.setString("url", link.getUrl());
        Link oldLink = (Link) query.uniqueResult();
        if (null != oldLink)
            return oldLink;

        session.save(link);
        if (null == link.getShortCode()) {
            link.setShortCode(generateShortcode(session));
            link.setClicks(new Long(0));
            link.setCreated(new Date(new java.util.Date().getTime()));
            session.save(link);
        }
        session.getTransaction().commit();
        return link;
    }

    public void incrementClicks(Link link) {
        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
        session.beginTransaction();
        Query query = session.createQuery("from Link where url = :url");
        query.setString("url", link.getUrl());

        Link oldLink = (Link) query.uniqueResult();
        oldLink.setClicks(oldLink.getClicks() + 1);

        session.getTransaction().commit();
    }

    private boolean existsShortcode(String shortcode, Session session) {
        Query query = session.createQuery("from Link where shortcode = :code");
        query.setString("code", shortcode);
        Link link = (Link) query.uniqueResult();
        return (link != null);
    }

    /**
     * Generate a short url which has not been assigned to any URL yet.
     * Or at least try 10 times :)
     */
    public String generateShortcode(Session session) {
        String shortcode;
        int attempts = 0;
        do {
            shortcode = HystqioUtils.generateShortCode();
            attempts++;
            // check if the shortcode doesn't already exist
        } while (existsShortcode(shortcode, session) && attempts < 10);
        if (attempts > 1) {
            log.error("WARNING: " + attempts + " attempts to create a shortcode which is not taken.");
        }
        return shortcode;
    }

}