org.grails.plugin.nativefinders.NativeFinderHandler.java Source code

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Here is the source code for org.grails.plugin.nativefinders.NativeFinderHandler.java

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/*
* Copyright (c) 2011 the original author or authors.
*
* 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 org.grails.plugin.nativefinders;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.IdentityHashMap;
import java.util.List;

import org.codehaus.groovy.ast.expr.ClosureExpression;
import org.codehaus.groovy.grails.commons.GrailsDomainClass;
import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsHibernateUtil;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.HibernateTemplate;

/**
 * Handle methods invocations for native finders.
 * 
 * @author Gabriel Velo
 * 
 */
public class NativeFinderHandler {

    private GrailsDomainClass domainClass;
    private SessionFactory sessionFactory;
    private IdentityHashMap<ClosureExpression, String> queryCache;

    public NativeFinderHandler(GrailsDomainClass domainClass, SessionFactory sessionFactory) {
        this.domainClass = domainClass;
        this.sessionFactory = sessionFactory;
        queryCache = new IdentityHashMap<ClosureExpression, String>();
    }

    public Object find(ClosureExpression closureExpression, final ArrayList parameters) {

        HibernateTemplate hibernateTemplate = new HibernateTemplate(sessionFactory);

        final String query = getQuery(domainClass.getName(), closureExpression, false);

        return hibernateTemplate.execute(new HibernateCallback<Object>() {
            public Object doInHibernate(Session session) throws HibernateException, SQLException {

                Query q = session.createQuery(query);

                for (int i = 0; i < parameters.size(); i++) {
                    q.setParameter(i, parameters.get(i));
                }

                // only want one result, could have used uniqueObject here
                // but it throws an exception if its not unique which is
                // undesirable
                q.setMaxResults(1);

                // TODO: add support for q.setCacheable()
                // q.setCacheable(useCache);

                List results = q.list();

                if (results.size() > 0) {
                    return GrailsHibernateUtil.unwrapIfProxy(results.get(0));
                }

                return null;

            }
        });

    }

    public Object findAll(ClosureExpression closureExpression, final ArrayList parameters) {

        HibernateTemplate hibernateTemplate = new HibernateTemplate(sessionFactory);

        final String query = getQuery(domainClass.getName(), closureExpression, false);

        return hibernateTemplate.executeFind(new HibernateCallback<Object>() {
            public Object doInHibernate(Session session) throws HibernateException, SQLException {

                Query q = session.createQuery(query);

                for (int i = 0; i < parameters.size(); i++) {
                    q.setParameter(i, parameters.get(i));
                }

                return q.list();

            }
        });

    }

    public Object count(ClosureExpression closureExpression, final ArrayList parameters) {

        HibernateTemplate hibernateTemplate = new HibernateTemplate(sessionFactory);

        final String query = getQuery(domainClass.getName(), closureExpression, true);

        return hibernateTemplate.execute(new HibernateCallback<Object>() {
            public Object doInHibernate(Session session) throws HibernateException, SQLException {

                Query q = session.createQuery(query);

                for (int i = 0; i < parameters.size(); i++) {
                    q.setParameter(i, parameters.get(i));
                }

                return q.uniqueResult();

            }
        });

    }

    private String getQuery(String className, ClosureExpression closureExpression, boolean isCount) {

        String query = null;

        synchronized (queryCache) {
            query = queryCache.get(closureExpression);
        }

        if (query == null) {

            Closure2HQL closure2HQL = new Closure2HQL();

            query = closure2HQL.buildQuery(className, closureExpression, isCount);

            synchronized (queryCache) {
                queryCache.put(closureExpression, query);
            }

        }

        return query;

    }

}