org.eclipse.persistence.internal.jpa.jpql.AbstractRangeDeclaration Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink
EclipseLink build based upon Git transaction 346465e
There is a newer version: 5.0.0-B07
/*******************************************************************************
 * Copyright (c) 2011, 2013 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation
 *
 ******************************************************************************/
package org.eclipse.persistence.internal.jpa.jpql;

import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import org.eclipse.persistence.jpa.jpql.parser.IdentificationVariableDeclaration;
import org.eclipse.persistence.jpa.jpql.parser.Join;
import org.eclipse.persistence.jpa.jpql.parser.RangeVariableDeclaration;

/**
 * The abstract definition of a range declaration, which is used to navigate to a "root" object.
 *
 * @see DerivedDeclaration
 * @see RangeDeclaration
 *
 * @version 2.4
 * @since 2.4
 * @author Pascal Filion
 */
abstract class AbstractRangeDeclaration extends Declaration {

	/**
	 * The list of JOIN expressions that are declared in the same declaration than the
	 * range variable declaration.
	 */
	List joins;

	/**
	 * Creates a new AbstractRangeDeclaration.
	 *
	 * @param queryContext The context used to query information about the application metadata and
	 * cached information
	 */
	AbstractRangeDeclaration(JPQLQueryContext queryContext) {
		super(queryContext);
	}

	/**
	 * Adds the given {@link Join} with its identification variable, which can be null.
	 *
	 * @param join The {@link Join} that was found in the list of joins
	 */
	void addJoin(Join join) {
		if (joins == null) {
			joins = new LinkedList();
		}
		joins.add(join);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public RangeVariableDeclaration getBaseExpression() {
		return (RangeVariableDeclaration) super.getBaseExpression();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public IdentificationVariableDeclaration getDeclarationExpression() {
		return (IdentificationVariableDeclaration) super.getDeclarationExpression();
	}

	/**
	 * Returns the JOIN expressions that were part of the range variable declaration in the
	 * ordered they were parsed.
	 *
	 * @return The ordered list of JOIN expressions or an empty collection if none was present
	 */
	public List getJoins() {
		return (joins == null) ? Collections.emptyList() : joins;
	}

	/**
	 * Determines whether the declaration contains JOIN expressions.
	 *
	 * @return true if at least one JOIN expression was parsed; otherwise
	 * false
	 */
	public boolean hasJoins() {
		return joins != null;
	}

	/**
	 * {@inheritDoc}
	 */
	public final boolean isCollection() {
		return false;
	}
}