gr.interamerican.bo2.impl.open.hibernate.AbstractHqlQuery.java Source code

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Here is the source code for gr.interamerican.bo2.impl.open.hibernate.AbstractHqlQuery.java

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/*******************************************************************************
 * Copyright (c) 2013 INTERAMERICAN PROPERTY AND CASUALTY INSURANCE COMPANY S.A. 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v3
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/copyleft/lesser.html
 * 
 * This library 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 Lesser General Public License for more details.
 ******************************************************************************/
package gr.interamerican.bo2.impl.open.hibernate;

import gr.interamerican.bo2.arch.PersistentObject;
import gr.interamerican.bo2.arch.ext.TypedSelectable;
import gr.interamerican.bo2.impl.open.annotations.Parameter;
import gr.interamerican.bo2.impl.open.hibernate.types.EntryUserType;
import gr.interamerican.bo2.impl.open.hibernate.types.UserTypeUtil;
import gr.interamerican.bo2.utils.sql.types.Type;
import gr.interamerican.bo2.utils.sql.types.TypeUtils;

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

/**
 * Abstract implementation of {@link AbstractHibernateQuery} based on HQL.
 * 
 * Fields annotated with {@link Parameter} are used as query named parameters.
 * If a field is a java bean, then all its properties are assumed to be
 * query named parameters. 
 * 
 * @param <P> result row type 
 *
 */
public abstract class AbstractHqlQuery<P> extends AbstractHibernateQuery<P> {

    /**
     * Creates a new AbstractHqlQuery object. 
     * 
     * This protected constructor is mainly intended for use by
     * public no argument constructors of sub-classes.
     *
     */
    protected AbstractHqlQuery() {
        super();
    }

    /**
     * HQL statement of the query.
     * 
     * @return Returns the HQL string for the query.
     */
    protected abstract String hql();

    /**
     * Query parameters.
     * 
     * @return Returns the query parameters.
     */
    protected Map<String, Object> parameters() {
        return this.getNamedParameters();
    }

    /**
     * Sets a parameter to a query.
     * 
     * If the parameter is of a type that is handled with a custom Bo2
     * hibernate user type, then it is handled accordingly. The association
     * between Bo2 hibernate user types and types they handle can be found
     * in {@link UserTypeUtil}.
     * 
     * If a parameter of such as type is passed to the query that is not handled
     * as a custom user type in the corresponding mappings, an error will ensue.
     * 
     * For example:
     * Branch is {@link TypedSelectable} (i.e. a type represented with the 
     * custom hibernate user type {@link EntryUserType}, but is also a 
     * {@link PersistentObject} that has its own hibernate mapping file.
     * Therefore, a {@link Parameter} of type Branch should not be passed
     * in an {@link AbstractHqlQuery}!!!
     * 
     * @param query
     *        Query on which the parameter is set.
     * @param name
     *        Name of the parameter.
     * @param parm
     *        Value of the parameter.
     */
    private void setParameter(org.hibernate.Query query, String name, Object parm) {
        if (UserTypeUtil.isUserType(parm)) {
            query.setParameter(name, parm);
        } else if (parm instanceof List<?>) {
            query.setParameterList(name, (List<?>) parm);
        } else if (parm instanceof Object[]) {
            query.setParameterList(name, (Object[]) parm);
        } else {
            @SuppressWarnings("rawtypes")
            Type type = TypeUtils.getType(parm);
            @SuppressWarnings("unchecked")
            Object parameter = type.statementParameter(parm);
            query.setParameter(name, parameter);

            /*
             *   ??
             * query.setEntity(name, parm);
             */
        }
    }

    @Override
    protected Iterator<?> createIterator() {
        org.hibernate.Query query = session.createQuery(hql());
        if (parameters() != null) {
            for (Map.Entry<String, Object> entry : parameters().entrySet()) {
                String name = entry.getKey();
                Object parm = entry.getValue();
                setParameter(query, name, parm);
            }
        }
        return query.iterate();
    }

}