wicket.contrib.phonebook.HibernateContactDao.java Source code

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Here is the source code for wicket.contrib.phonebook.HibernateContactDao.java

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/*
 * $Id: HibernateContactDao.java 1056 2006-10-27 22:49:28Z ivaynberg $
 * $Revision: 1056 $
 * $Date: 2006-10-27 15:49:28 -0700 (Fri, 27 Oct 2006) $
 *
 * ==============================================================================
 * 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 wicket.contrib.phonebook;

import java.util.Iterator;
import java.util.List;

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

/**
 * implements {@link ContactDao}.
 * 
 * @author igor
 */
public class HibernateContactDao implements ContactDao {

    private SessionFactory factory;

    /**
     * Setter for session factory. Spring will use this to inject the session factory into the dao.
     * 
     * @param factory
     *            hibernate session factory
     */
    public void setSessionFactory(SessionFactory factory) {
        this.factory = factory;
    }

    /**
     * Helper method for retrieving hibernate session
     * 
     * @return hibernate session
     */
    protected Session getSession() {
        return factory.getCurrentSession();
    }

    /**
     * Load a {@link Contact} from the DB, given it's <tt>id</tt> .
     * 
     * @param id
     *            The id of the Contact to load.
     * @return Contact
     */
    public Contact load(long id) {
        return (Contact) getSession().get(Contact.class, Long.valueOf(id));
    }

    /**
     * Save the contact to the DB
     * 
     * @param contact
     * @return persistent instance of contact
     */
    public Contact save(Contact contact) {
        return (Contact) getSession().merge(contact);
    }

    /**
     * Delete a {@link Contact} from the DB, given it's <tt>id</tt>.
     * 
     * @param id
     *            The id of the Contact to delete.
     */
    public void delete(long id) {
        getSession().delete(load(id));
    }

    /**
     * Query the DB, using the supplied query details.
     * 
     * @param qp
     *            Query Parameters to use.
     * @return The results of the query as an Iterator.
     */
    @SuppressWarnings("unchecked")
    public Iterator<Contact> find(final QueryParam qp, Contact filter) {
        return buildFindQuery(qp, filter, false).list().iterator();

    }

    /**
     * Return the number of Contacts in the DB.
     * 
     * @return count
     */
    public int count(Contact filter) {
        return ((Long) buildFindQuery(null, filter, true).uniqueResult()).intValue();
    }

    /**
     * Returns a list of unique last names
     */
    @SuppressWarnings("unchecked")
    public List<String> getUniqueLastNames() {
        return getSession()
                .createQuery("select distinct target.lastname " + " from Contact target order by target.lastname")
                .list();
    }

    /**
     * builds a query object to satisfy the provided parameters
     * 
     * @param qp
     *            sorting and paging criteria
     * @param filter
     *            filter criteria
     * @param count
     *            true if this is a query meant to retrieve the number of rows
     * @return query object that satisfies the provided criteria
     */
    protected Query buildFindQuery(QueryParam qp, Contact filter, boolean count) {
        HibernateContactFinderQueryBuilder builder = new HibernateContactFinderQueryBuilder();
        builder.setQueryParam(qp);
        builder.setFilter(filter);
        builder.setCount(count);
        Query query = getSession().createQuery(builder.buildHql());
        query.setParameters(builder.getParameters(), builder.getTypes());
        if (!count && qp != null) {
            query.setFirstResult((int) qp.getFirst()).setMaxResults((int) qp.getCount());
        }
        return query;
    }

}