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/*
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* Copyright (c) 2008, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package com.sun.beans.decoder;
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/**
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* This class is intended to handle <null> element.
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* This element specifies {@code null} value.
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* It should not contain body or inner elements.
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* For example:<pre>
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* <null/></pre>
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* is equivalent to {@code null} in Java code.
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* <p>The following attribute is supported:
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* <dl>
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* <dt>id
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* <dd>the identifier of the variable that is intended to store the result
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* </dl>
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*
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* @since 1.7
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*
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* @author Sergey A. Malenkov
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*/
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class NullElementHandler extends ElementHandler implements ValueObject {
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/**
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* Returns the value of this element.
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*
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* @return the value of this element
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*/
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@Override
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protected final ValueObject getValueObject() {
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return this;
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}
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/**
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* Returns {@code null}
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* as a value of <null> element.
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* This method should be overridden in those handlers
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* that extend behavior of this element.
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*
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* @return {@code null} by default
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*/
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public Object getValue() {
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return null;
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}
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/**
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* Returns {@code void} state of this value object.
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*
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* @return {@code false} always
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*/
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public final boolean isVoid() {
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return false;
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}
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}
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