1 /*
2 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.lang.model.util;
27
28
29 import javax.lang.model.element.*;
30
31 import static javax.lang.model.SourceVersion.*;
32 import javax.lang.model.SourceVersion;
33 import javax.annotation.processing.SupportedSourceVersion;
34
35 /**
36 * A skeletal visitor for annotation values with default behavior
37 * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
38 * source version.
39 *
40 * <p> <b>WARNING:</b> The {@code AnnotationValueVisitor} interface
41 * implemented by this class may have methods added to it in the
42 * future to accommodate new, currently unknown, language structures
43 * added to future versions of the Java™ programming language.
44 * Therefore, methods whose names begin with {@code "visit"} may be
45 * added to this class in the future; to avoid incompatibilities,
46 * classes which extend this class should not declare any instance
47 * methods with names beginning with {@code "visit"}.
48 *
49 * <p>When such a new visit method is added, the default
50 * implementation in this class will be to call the {@link
51 * #visitUnknown visitUnknown} method. A new abstract annotation
52 * value visitor class will also be introduced to correspond to the
53 * new language level; this visitor will have different default
54 * behavior for the visit method in question. When the new visitor is
55 * introduced, all or portions of this visitor may be deprecated.
56 *
57 * @param <R> the return type of this visitor's methods
58 * @param <P> the type of the additional parameter to this visitor's methods.
59 *
60 * @author Joseph D. Darcy
61 * @author Scott Seligman
62 * @author Peter von der Ahé
63 *
64 * @see AbstractAnnotationValueVisitor7
65 * @see AbstractAnnotationValueVisitor8
66 * @since 1.6
67 */
68 @SupportedSourceVersion(RELEASE_6)
69 public abstract class AbstractAnnotationValueVisitor6<R, P>
70 implements AnnotationValueVisitor<R, P> {
71
72 /**
73 * Constructor for concrete subclasses to call.
74 */
75 protected AbstractAnnotationValueVisitor6() {}
76
77 /**
78 * Visits an annotation value as if by passing itself to that
79 * value's {@link AnnotationValue#accept accept}. The invocation
80 * {@code v.visit(av)} is equivalent to {@code av.accept(v, p)}.
81 * @param av {@inheritDoc}
82 * @param p {@inheritDoc}
83 */
84 public final R visit(AnnotationValue av, P p) {
85 return av.accept(this, p);
86 }
87
88 /**
89 * Visits an annotation value as if by passing itself to that
90 * value's {@link AnnotationValue#accept accept} method passing
91 * {@code null} for the additional parameter. The invocation
92 * {@code v.visit(av)} is equivalent to {@code av.accept(v,
93 * null)}.
94 * @param av {@inheritDoc}
95 */
96 public final R visit(AnnotationValue av) {
97 return av.accept(this, null);
98 }
99
100 /**
101 * {@inheritDoc}
102 *
103 * <p>The default implementation of this method in {@code
104 * AbstractAnnotationValueVisitor6} will always throw {@code
105 * UnknownAnnotationValueException}. This behavior is not
106 * required of a subclass.
107 *
108 * @param av {@inheritDoc}
109 * @param p {@inheritDoc}
110 */
111 public R visitUnknown(AnnotationValue av, P p) {
112 throw new UnknownAnnotationValueException(av, p);
113 }
114 }