1 /*
2 * Copyright (c) 2005, 2020, 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 * @apiNote
41 * <p id=note_for_subclasses><strong>WARNING:</strong> The {@code
42 * AnnotationValueVisitor} interface implemented by this class may
43 * have methods added to it in the future to accommodate new,
44 * currently unknown, language structures added to future versions of
45 * the Java programming language. Therefore, methods whose
46 * names begin with {@code "visit"} may be added to this class in the
47 * future; to avoid incompatibilities, classes and subclasses which
48 * extend this class should not declare any instance methods with
49 * names beginning with {@code "visit"}.</p>
50 *
51 * <p>When such a new visit method is added, the default
52 * implementation in this class will be to directly or indirectly call
53 * the {@link #visitUnknown visitUnknown} method. A new abstract
54 * annotation value visitor class will also be introduced to
55 * correspond to the new language level; this visitor will have
56 * different default behavior for the visit method in question. When
57 * a new visitor is introduced, portions of this visitor class may be
58 * deprecated, including its constructors.
59 *
60 * @param <R> the return type of this visitor's methods
61 * @param <P> the type of the additional parameter to this visitor's methods.
62 *
63 * @author Joseph D. Darcy
64 * @author Scott Seligman
65 * @author Peter von der Ahé
66 *
67 * @see AbstractAnnotationValueVisitor7
68 * @see AbstractAnnotationValueVisitor8
69 * @see AbstractAnnotationValueVisitor9
70 * @see AbstractAnnotationValueVisitor14
71 * @since 1.6
72 */
73 @SupportedSourceVersion(RELEASE_6)
74 public abstract class AbstractAnnotationValueVisitor6<R, P>
75 implements AnnotationValueVisitor<R, P> {
76
77 /**
78 * Constructor for concrete subclasses to call.
79 * @deprecated Release 6 is obsolete; update to a visitor for a newer
80 * release level.
81 */
82 @Deprecated(since="9")
83 protected AbstractAnnotationValueVisitor6() {}
84
85 /**
86 * Visits any annotation value as if by passing itself to that
87 * value's {@link AnnotationValue#accept accept}. The invocation
88 * {@code v.visit(av, p)} is equivalent to {@code av.accept(v, p)}.
89 * @param av {@inheritDoc}
90 * @param p {@inheritDoc}
91 * @return {@inheritDoc}
92 */
93 public final R visit(AnnotationValue av, P p) {
94 return av.accept(this, p);
95 }
96
97 /**
98 * Visits an annotation value as if by passing itself to that
99 * value's {@link AnnotationValue#accept accept} method passing
100 * {@code null} for the additional parameter. The invocation
101 * {@code v.visit(av)} is equivalent to {@code av.accept(v,
102 * null)}.
103 * @param av {@inheritDoc}
104 * @return {@inheritDoc}
105 */
106 public final R visit(AnnotationValue av) {
107 return av.accept(this, null);
108 }
109
110 /**
111 * {@inheritDoc}
112 *
113 * @implSpec The default implementation of this method in {@code
114 * AbstractAnnotationValueVisitor6} will always throw {@code
115 * new UnknownAnnotationValueException(av, p)}. This behavior is not
116 * required of a subclass.
117 *
118 * @param av {@inheritDoc}
119 * @param p {@inheritDoc}
120 * @return {@inheritDoc}
121 */
122 @Override
123 public R visitUnknown(AnnotationValue av, P p) {
124 throw new UnknownAnnotationValueException(av, p);
125 }
126 }