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JPA support for Querydsl

There is a newer version: 3.7.4

/*
 * Copyright 2011, Mysema Ltd
 * 
 * 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 com.mysema.query.jpa;

import java.util.Iterator;

import javax.persistence.Query;

import org.hibernate.ScrollMode;
import org.hibernate.ScrollableResults;
import org.hibernate.ejb.HibernateQuery;
import org.hibernate.transform.ResultTransformer;

import com.mysema.commons.lang.CloseableIterator;
import com.mysema.commons.lang.IteratorAdapter;
import com.mysema.query.types.FactoryExpression;

/**
 * @author tiwe
 *
 */
public class HibernateHandler implements QueryHandler {

    @Override
    public  CloseableIterator iterate(Query query, FactoryExpression projection) {
        if (query instanceof HibernateQuery) {
            HibernateQuery hQuery = (HibernateQuery)query;
            ScrollableResults results = hQuery.getHibernateQuery().scroll(ScrollMode.FORWARD_ONLY);
            CloseableIterator iterator = new ScrollableResultsIterator(results);
            if (projection != null) {
                iterator = new TransformingIterator(iterator, projection);
            }
            return iterator;
        } else {
            Iterator iterator = query.getResultList().iterator();
            if (projection != null) {
                return new TransformingIterator(iterator, projection);                
            } else {
                return new IteratorAdapter(iterator);
            }        
        }        
    }
    
    @Override
    public boolean transform(Query query, FactoryExpression projection) {
        if (query instanceof HibernateQuery) {
            ResultTransformer transformer = new FactoryExpressionTransformer(projection); 
            ((HibernateQuery)query).getHibernateQuery().setResultTransformer(transformer);
            return true;
        } else {
            return false;
        }
    }

}