1 /*
2 * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package javax.xml.bind;
27 import javax.xml.namespace.QName;
28
29 /**
30 * Provide access to JAXB xml binding data for a JAXB object.
31 *
32 * <p>
33 * Intially, the intent of this class is to just conceptualize how
34 * a JAXB application developer can access xml binding information,
35 * independent if binding model is java to schema or schema to java.
36 * Since accessing the XML element name related to a JAXB element is
37 * a highly requested feature, demonstrate access to this
38 * binding information.
39 *
40 * The factory method to get a <code>JAXBIntrospector</code> instance is
41 * {@link JAXBContext#createJAXBIntrospector()}.
42 *
43 * @see JAXBContext#createJAXBIntrospector()
44 * @since JAXB2.0
45 */
46 public abstract class JAXBIntrospector {
47
48 /**
49 * <p>Return true iff <code>object</code> represents a JAXB element.</p>
50 * <p>Parameter <code>object</code> is a JAXB element for following cases:
51 * <ol>
52 * <li>It is an instance of <code>javax.xml.bind.JAXBElement</code>.</li>
53 * <li>The class of <code>object</code> is annotated with
54 * <code>@XmlRootElement</code>.
55 * </li>
56 * </ol>
57 *
58 * @see #getElementName(Object)
59 */
60 public abstract boolean isElement(Object object);
61
62 /**
63 * <p>Get xml element qname for <code>jaxbElement</code>.</p>
64 *
65 * @param jaxbElement is an object that {@link #isElement(Object)} returned true.
66 *
67 * @return xml element qname associated with jaxbElement;
68 * null if <code>jaxbElement</code> is not a JAXB Element.
69 */
70 public abstract QName getElementName(Object jaxbElement);
71
72 /**
73 * <p>Get the element value of a JAXB element.</p>
74 *
75 * <p>Convenience method to abstract whether working with either
76 * a javax.xml.bind.JAXBElement instance or an instance of
77 * <tt>@XmlRootElement</tt> annotated Java class.</p>
78 *
79 * @param jaxbElement object that #isElement(Object) returns true.
80 *
81 * @return The element value of the <code>jaxbElement</code>.
82 */
83 public static Object getValue(Object jaxbElement) {
84 if (jaxbElement instanceof JAXBElement) {
85 return ((JAXBElement)jaxbElement).getValue();
86 } else {
87 // assume that class of this instance is
88 // annotated with @XmlRootElement.
89 return jaxbElement;
90 }
91 }
92 }
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