1 /*
2 * Copyright (c) 2005, 2010, 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 java.util.List;
30 import javax.lang.model.element;
31
32 import javax.lang.model.type.TypeMirror;
33 import static javax.lang.model.SourceVersion.*;
34 import javax.lang.model.SourceVersion;
35 import javax.annotation.processing.SupportedSourceVersion;
36
37 /**
38 * A simple visitor for annotation values with default behavior
39 * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
40 * source version. Visit methods call {@link
41 * #defaultAction} passing their arguments to {@code defaultAction}'s
42 * corresponding parameters.
43 *
44 * <p> Methods in this class may be overridden subject to their
45 * general contract. Note that annotating methods in concrete
46 * subclasses with {@link java.lang.Override @Override} will help
47 * ensure that methods are overridden as intended.
48 *
49 * <p> <b>WARNING:</b> The {@code AnnotationValueVisitor} interface
50 * implemented by this class may have methods added to it in the
51 * future to accommodate new, currently unknown, language structures
52 * added to future versions of the Java™ programming language.
53 * Therefore, methods whose names begin with {@code "visit"} may be
54 * added to this class in the future; to avoid incompatibilities,
55 * classes which extend this class should not declare any instance
56 * methods with names beginning with {@code "visit"}.
57 *
58 * <p>When such a new visit method is added, the default
59 * implementation in this class will be to call the {@link
60 * #visitUnknown visitUnknown} method. A new simple annotation
61 * value visitor class will also be introduced to correspond to the
62 * new language level; this visitor will have different default
63 * behavior for the visit method in question. When the new visitor is
64 * introduced, all or portions of this visitor may be deprecated.
65 *
66 * @param <R> the return type of this visitor's methods
67 * @param <P> the type of the additional parameter to this visitor's methods.
68 *
69 * @author Joseph D. Darcy
70 * @author Scott Seligman
71 * @author Peter von der Ahé
72 *
73 * @see SimpleAnnotationValueVisitor7
74 * @since 1.6
75 */
76 @SupportedSourceVersion(RELEASE_6)
77 public class SimpleAnnotationValueVisitor6<R, P>
78 extends AbstractAnnotationValueVisitor6<R, P> {
79
80 /**
81 * Default value to be returned; {@link #defaultAction
82 * defaultAction} returns this value unless the method is
83 * overridden.
84 */
85 protected final R DEFAULT_VALUE;
86
87 /**
88 * Constructor for concrete subclasses; uses {@code null} for the
89 * default value.
90 */
91 protected SimpleAnnotationValueVisitor6() {
92 super();
93 DEFAULT_VALUE = null;
94 }
95
96 /**
97 * Constructor for concrete subclasses; uses the argument for the
98 * default value.
99 *
100 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
101 */
102 protected SimpleAnnotationValueVisitor6(R defaultValue) {
103 super();
104 DEFAULT_VALUE = defaultValue;
105 }
106
107 /**
108 * The default action for visit methods. The implementation in
109 * this class just returns {@link #DEFAULT_VALUE}; subclasses will
110 * commonly override this method.
111 *
112 * @param o the value of the annotation
113 * @param p a visitor-specified parameter
114 * @return {@code DEFAULT_VALUE} unless overridden
115 */
116 protected R defaultAction(Object o, P p) {
117 return DEFAULT_VALUE;
118 }
119
120 /**
121 * {@inheritDoc} This implementation calls {@code defaultAction}.
122 *
123 * @param b {@inheritDoc}
124 * @param p {@inheritDoc}
125 * @return the result of {@code defaultAction}
126 */
127 public R visitBoolean(boolean b, P p) {
128 return defaultAction(b, p);
129 }
130
131 /**
132 * {@inheritDoc} This implementation calls {@code defaultAction}.
133 *
134 * @param b {@inheritDoc}
135 * @param p {@inheritDoc}
136 * @return the result of {@code defaultAction}
137 */
138 public R visitByte(byte b, P p) {
139 return defaultAction(b, p);
140 }
141
142 /**
143 * {@inheritDoc} This implementation calls {@code defaultAction}.
144 *
145 * @param c {@inheritDoc}
146 * @param p {@inheritDoc}
147 * @return the result of {@code defaultAction}
148 */
149 public R visitChar(char c, P p) {
150 return defaultAction(c, p);
151 }
152
153 /**
154 * {@inheritDoc} This implementation calls {@code defaultAction}.
155 *
156 * @param d {@inheritDoc}
157 * @param p {@inheritDoc}
158 * @return the result of {@code defaultAction}
159 */
160 public R visitDouble(double d, P p) {
161 return defaultAction(d, p);
162 }
163
164 /**
165 * {@inheritDoc} This implementation calls {@code defaultAction}.
166 *
167 * @param f {@inheritDoc}
168 * @param p {@inheritDoc}
169 * @return the result of {@code defaultAction}
170 */
171 public R visitFloat(float f, P p) {
172 return defaultAction(f, p);
173 }
174
175 /**
176 * {@inheritDoc} This implementation calls {@code defaultAction}.
177 *
178 * @param i {@inheritDoc}
179 * @param p {@inheritDoc}
180 * @return the result of {@code defaultAction}
181 */
182 public R visitInt(int i, P p) {
183 return defaultAction(i, p);
184 }
185
186 /**
187 * {@inheritDoc} This implementation calls {@code defaultAction}.
188 *
189 * @param i {@inheritDoc}
190 * @param p {@inheritDoc}
191 * @return the result of {@code defaultAction}
192 */
193 public R visitLong(long i, P p) {
194 return defaultAction(i, p);
195 }
196
197 /**
198 * {@inheritDoc} This implementation calls {@code defaultAction}.
199 *
200 * @param s {@inheritDoc}
201 * @param p {@inheritDoc}
202 * @return the result of {@code defaultAction}
203 */
204 public R visitShort(short s, P p) {
205 return defaultAction(s, p);
206 }
207
208 /**
209 * {@inheritDoc} This implementation calls {@code defaultAction}.
210 *
211 * @param s {@inheritDoc}
212 * @param p {@inheritDoc}
213 * @return the result of {@code defaultAction}
214 */
215 public R visitString(String s, P p) {
216 return defaultAction(s, p);
217 }
218
219 /**
220 * {@inheritDoc} This implementation calls {@code defaultAction}.
221 *
222 * @param t {@inheritDoc}
223 * @param p {@inheritDoc}
224 * @return the result of {@code defaultAction}
225 */
226 public R visitType(TypeMirror t, P p) {
227 return defaultAction(t, p);
228 }
229
230 /**
231 * {@inheritDoc} This implementation calls {@code defaultAction}.
232 *
233 * @param c {@inheritDoc}
234 * @param p {@inheritDoc}
235 * @return the result of {@code defaultAction}
236 */
237 public R visitEnumConstant(VariableElement c, P p) {
238 return defaultAction(c, p);
239 }
240
241 /**
242 * {@inheritDoc} This implementation calls {@code defaultAction}.
243 *
244 * @param a {@inheritDoc}
245 * @param p {@inheritDoc}
246 * @return the result of {@code defaultAction}
247 */
248 public R visitAnnotation(AnnotationMirror a, P p) {
249 return defaultAction(a, p);
250 }
251
252 /**
253 * {@inheritDoc} This implementation calls {@code defaultAction}.
254 *
255 * @param vals {@inheritDoc}
256 * @param p {@inheritDoc}
257 * @return the result of {@code defaultAction}
258 */
259 public R visitArray(List<? extends AnnotationValue> vals, P p) {
260 return defaultAction(vals, p);
261 }
262 }