org.gbif.portal.dao.impl.hibernate.SimpleQueryDAOImpl.java Source code

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/***************************************************************************
 * Copyright (C) 2005 Global Biodiversity Information Facility Secretariat.
 * All Rights Reserved.
 *
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 ***************************************************************************/
package org.gbif.portal.dao.impl.hibernate;

import java.io.IOException;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.gbif.portal.dao.AssociationTraverser;
import org.gbif.portal.dao.DAOUtils;
import org.gbif.portal.dao.SimpleQueryDAO;
import org.gbif.portal.io.ResultsOutputter;
import org.hibernate.CacheMode;
import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
 * Implementation of SimpleQueryDAO that allows for untyped queries.
 * 
 * @author dmartin
 */
public class SimpleQueryDAOImpl extends HibernateDaoSupport implements SimpleQueryDAO {

    protected static Log logger = LogFactory.getLog(SimpleQueryDAOImpl.class);

    /** Object used to process the associations and produce a object array */
    protected AssociationTraverser associationTraverser;

    /** Batch size used for pre processing of results */
    protected int batchSize = 1000;

    /**
     * @see org.gbif.portal.dao.SimpleQueryDAO#getByQuery(java.lang.String, java.util.List, java.lang.Integer)
     */
    @SuppressWarnings("unchecked")
    public List getByQuery(final String queryString, final List<Object> parameters, final Integer startIndex,
            final Integer maxResults) {
        if (logger.isDebugEnabled()) {
            logger.debug("GetByQuery running with startIndex[" + startIndex + "], maxResults[" + maxResults + "]");
        }
        HibernateTemplate template = getHibernateTemplate();
        return (List) template.execute(new HibernateCallback() {
            public Object doInHibernate(Session session) {
                if (logger.isDebugEnabled())
                    logger.debug("getByQuery queryString " + queryString);
                Query query = createQuery(queryString, parameters, startIndex, maxResults, session);
                return query.list();
            }
        });
    }

    /**
     * @see org.gbif.portal.dao.SimpleQueryDAO#outputResultsForQuery(java.lang.String, java.util.List, java.lang.Integer, java.lang.Integer)
     */
    public void outputResultsForQuery(final String queryString, final List<Object> parameters,
            final Integer startIndex, final Integer maxResults, final ResultsOutputter resultsOutputter)
            throws IOException {

        Session session = getSession();
        session.setCacheMode(CacheMode.IGNORE);

        if (logger.isDebugEnabled())
            logger.debug("getByQuery queryString " + queryString);
        Query query = createQuery(queryString, parameters, startIndex, maxResults, session);
        DAOUtils.scrollResults(resultsOutputter, session, query, associationTraverser, batchSize);
    }

    /**
     * Create the query setting the positional parameters and limits.
     * 
     * @param queryString
     * @param parameters
     * @param startIndex
     * @param maxResults
     * @param session
     * @return query ready for execution
     */
    private Query createQuery(final String queryString, final List<Object> parameters, final Integer startIndex,
            final Integer maxResults, Session session) {
        Query query = session.createQuery(queryString);
        if (parameters != null) {
            int positionalParamIdx = 0;
            for (int i = 0; i < parameters.size(); i++) {
                // note that the parameter type is inferred here...
                if (logger.isDebugEnabled())
                    logger.debug("getByQuery setting parameter " + i + " : " + parameters.get(i));
                if (parameters.get(i) == null) {
                    //nulls are handled by not adding
                    //any position parameters - setting a position parameter
                    //to null or 'null' results in hibernate compiling it down to
                    //latitude !=null which behaves differently to is not null
                } else if (parameters.get(i) instanceof Collection) {
                    Collection collection = (Collection) parameters.get(i);
                    for (Iterator iter = collection.iterator(); iter.hasNext();) {
                        Object parameter = (Object) iter.next();
                        query.setParameter(positionalParamIdx, parameter);
                        positionalParamIdx++;
                    }
                } else if (parameters.get(i) instanceof Date) {
                    query.setTimestamp(positionalParamIdx, (Date) parameters.get(i));
                    positionalParamIdx++;
                } else {
                    query.setParameter(positionalParamIdx, parameters.get(i));
                    positionalParamIdx++;
                }
            }
        }
        if (startIndex != null)
            query.setFirstResult(startIndex);
        if (maxResults != null)
            query.setMaxResults(maxResults);
        return query;
    }

    /**
     * @param associationTraverser the associationTraverser to set
     */
    public void setAssociationTraverser(AssociationTraverser associationTraverser) {
        this.associationTraverser = associationTraverser;
    }
}