77 lines
2.4 KiB
Java
77 lines
2.4 KiB
Java
/*
|
|
* 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>
|
|
* <null/></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;
|
|
}
|
|
}
|