/*

 * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.beans.decoder;

/**

 * This class is intended to handle <null> element.

 * This element specifies {@code null} value.

 * It should not contain body or inner elements.

 * For example:<pre>

 * &lt;null/&gt;</pre>

 * is equivalent to {@code null} in Java code.

 * <p>The following attribute is supported:

 * <dl>

 * <dt>id

 * <dd>the identifier of the variable that is intended to store the result

 * </dl>

 *

 * @since 1.7

 *

 * @author Sergey A. Malenkov

 */

class NullElementHandler extends ElementHandler implements ValueObject {

    /**

     * Returns the value of this element.

     *

     * @return the value of this element

     */

    @Override

    protected final ValueObject getValueObject() {

        return this;

    }

    /**

     * Returns {@code null}

     * as a value of <null> element.

     * This method should be overridden in those handlers

     * that extend behavior of this element.

     *

     * @return {@code null} by default

     */

    public Object getValue() {

        return null;

    }

    /**

     * Returns {@code void} state of this value object.

     *

     * @return {@code false} always

     */

    public final boolean isVoid() {

        return false;

    }

}