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Extensible parser for HQL/JP-QL queries
There is a newer version: 1.5.0.Final
/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * JBoss, Home of Professional Open Source
 * Copyright 2013 Red Hat Inc. and/or its affiliates and other contributors
 * as indicated by the @authors tag. All rights reserved.
 * See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU Lesser General Public License, v. 2.1.
 * This program is distributed in the hope that it will be useful, but WITHOUT A
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
 * You should have received a copy of the GNU Lesser General Public License,
 * v.2.1 along with this distribution; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 */
package org.hibernate.hql.ast.spi;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Stack;

import org.hibernate.hql.ast.spi.predicate.ComparisonPredicate.Type;
import org.hibernate.hql.ast.spi.predicate.ParentPredicate;
import org.hibernate.hql.ast.spi.predicate.Predicate;
import org.hibernate.hql.ast.spi.predicate.PredicateFactory;
import org.hibernate.hql.ast.spi.predicate.RootPredicate;

/**
 * Builder for the creation of queries targeting a single entity, based on HQL/JPQL queries.
 * 
 * Implemented as a stack of {@link Predicate}s which allows to add elements to the constructed query in a uniform
 * manner while traversing through the original HQL/JPQL query parse tree.
 *
 * @param  the type of query created by this builder
 * @author Gunnar Morling
 */
public final class SingleEntityQueryBuilder {

	private final PredicateFactory predicateFactory;
	private final PropertyHelper propertyHelper;

	/**
	 * The targeted entity type of the built query.
	 */
	private String entityType;

	/**
	 * The root predicate of the {@code WHERE} clause of the built query.
	 */
	private RootPredicate rootPredicate;

	/**
	 * Keeps track of all the parent predicates ({@code AND}, {@code OR} etc.) of the {@code WHERE} clause of the built
	 * query.
	 */
	private final Stack> predicates = new Stack>();

	private SingleEntityQueryBuilder(PredicateFactory predicateFactory, PropertyHelper propertyHelper) {
		this.predicateFactory = predicateFactory;
		this.propertyHelper = propertyHelper;
	}

	public static  SingleEntityQueryBuilder getInstance(PredicateFactory predicateFactory, PropertyHelper propertyHelper) {
		return new SingleEntityQueryBuilder( predicateFactory, propertyHelper );
	}

	public SingleEntityQueryBuilder setEntityType(String entityType) {
		this.entityType = entityType;

		rootPredicate = predicateFactory.getRootPredicate( entityType );
		predicates.push( rootPredicate );

		return this;
	}

	public SingleEntityQueryBuilder addComparisonPredicate(List propertyPath, Type comparisonType, Object value) {
		Object typedValue = propertyHelper.convertToBackendType( entityType, propertyPath, value );
		pushPredicate( predicateFactory.getComparisonPredicate( entityType, comparisonType, propertyPath, typedValue ) );

		return this;
	}

	public SingleEntityQueryBuilder addRangePredicate(String property, Object lower, Object upper) {
		return addRangePredicate( Collections.singletonList( property ), lower, upper );
	}

	public SingleEntityQueryBuilder addRangePredicate(List propertyPath, Object lower, Object upper) {
		Object lowerValue = propertyHelper.convertToBackendType( entityType, propertyPath, lower );
		Object upperValue = propertyHelper.convertToBackendType( entityType, propertyPath, upper );

		pushPredicate( predicateFactory.getRangePredicate( entityType, propertyPath, lowerValue, upperValue ) );

		return this;
	}

	public SingleEntityQueryBuilder addInPredicate(List propertyPath, List