EnumTypeStateObject.java

/*******************************************************************************
 * Copyright (c) 2011, 2015 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.jpa.jpql.tools.model.query;

import org.eclipse.persistence.jpa.jpql.parser.AbstractPathExpression;

/**
 * This {@link StateObject} wraps the name of an {@link Enum} constant.
 *
 * @version 2.4
 * @since 2.4
 * @author Pascal Filion
 */
@SuppressWarnings("nls")
public class EnumTypeStateObject extends SimpleStateObject {

    /**
     * Creates a new <code>EnumTypeStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public EnumTypeStateObject(StateObject parent) {
        super(parent);
    }

    /**
     * Creates a new <code>EnumTypeStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @param enumConstant The fully qualified name of the {@link Enum} type following by the constant
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public EnumTypeStateObject(StateObject parent, Enum<? extends Enum<?>> enumConstant) {
        super(parent, toString(enumConstant));
    }

    /**
     * Creates a new <code>EnumTypeStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @param enumConstant The fully qualified name of the {@link Enum} constant
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public EnumTypeStateObject(StateObject parent, String enumConstant) {
        super(parent, enumConstant);
    }

    private static String toString(Enum<? extends Enum<?>> enumConstant) {
        Class<?> enumType = enumConstant.getDeclaringClass();
        return enumType.getName() + "." + enumConstant.name();
    }

    /**
     * {@inheritDoc}
     */
    public void accept(StateObjectVisitor visitor) {
        visitor.visit(this);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public AbstractPathExpression getExpression() {
        return (AbstractPathExpression) super.getExpression();
    }

    /**
     * Keeps a reference of the {@link AbstractPathExpression parsed object} object, which should
     * only be done when this object is instantiated during the conversion of a parsed JPQL query
     * into {@link StateObject StateObjects}.
     *
     * @param expression The {@link AbstractPathExpression parsed object} representing the enum type
     */
    public void setExpression(AbstractPathExpression expression) {
        super.setExpression(expression);
    }
}