001 /*
002 * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package javax.lang.model.util;
027
028
029 import java.util.List;
030 import javax.lang.model.element.*;
031
032 import javax.lang.model.type.TypeMirror;
033 import static javax.lang.model.SourceVersion.*;
034 import javax.lang.model.SourceVersion;
035 import javax.annotation.processing.SupportedSourceVersion;
036
037 /**
038 * A simple visitor for annotation values with default behavior
039 * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
040 * source version. Visit methods call {@link
041 * #defaultAction} passing their arguments to {@code defaultAction}'s
042 * corresponding parameters.
043 *
044 * <p> Methods in this class may be overridden subject to their
045 * general contract. Note that annotating methods in concrete
046 * subclasses with {@link java.lang.Override @Override} will help
047 * ensure that methods are overridden as intended.
048 *
049 * <p> <b>WARNING:</b> The {@code AnnotationValueVisitor} interface
050 * implemented by this class may have methods added to it in the
051 * future to accommodate new, currently unknown, language structures
052 * added to future versions of the Java™ programming language.
053 * Therefore, methods whose names begin with {@code "visit"} may be
054 * added to this class in the future; to avoid incompatibilities,
055 * classes which extend this class should not declare any instance
056 * methods with names beginning with {@code "visit"}.
057 *
058 * <p>When such a new visit method is added, the default
059 * implementation in this class will be to call the {@link
060 * #visitUnknown visitUnknown} method. A new simple annotation
061 * value visitor class will also be introduced to correspond to the
062 * new language level; this visitor will have different default
063 * behavior for the visit method in question. When the new visitor is
064 * introduced, all or portions of this visitor may be deprecated.
065 *
066 * @param <R> the return type of this visitor's methods
067 * @param <P> the type of the additional parameter to this visitor's methods.
068 *
069 * @author Joseph D. Darcy
070 * @author Scott Seligman
071 * @author Peter von der Ahé
072 * @since 1.6
073 */
074 @SupportedSourceVersion(RELEASE_6)
075 public class SimpleAnnotationValueVisitor6<R, P>
076 extends AbstractAnnotationValueVisitor6<R, P> {
077
078 /**
079 * Default value to be returned; {@link #defaultAction
080 * defaultAction} returns this value unless the method is
081 * overridden.
082 */
083 protected final R DEFAULT_VALUE;
084
085 /**
086 * Constructor for concrete subclasses; uses {@code null} for the
087 * default value.
088 */
089 protected SimpleAnnotationValueVisitor6() {
090 super();
091 DEFAULT_VALUE = null;
092 }
093
094 /**
095 * Constructor for concrete subclasses; uses the argument for the
096 * default value.
097 *
098 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
099 */
100 protected SimpleAnnotationValueVisitor6(R defaultValue) {
101 super();
102 DEFAULT_VALUE = defaultValue;
103 }
104
105 /**
106 * The default action for visit methods. The implementation in
107 * this class just returns {@link #DEFAULT_VALUE}; subclasses will
108 * commonly override this method.
109 *
110 * @param o the value of the annotation
111 * @param p a visitor-specified parameter
112 * @return {@code DEFAULT_VALUE} unless overridden
113 */
114 protected R defaultAction(Object o, P p) {
115 return DEFAULT_VALUE;
116 }
117
118 /**
119 * {@inheritDoc} This implementation calls {@code defaultAction}.
120 *
121 * @param b {@inheritDoc}
122 * @param p {@inheritDoc}
123 * @return the result of {@code defaultAction}
124 */
125 public R visitBoolean(boolean b, P p) {
126 return defaultAction(b, p);
127 }
128
129 /**
130 * {@inheritDoc} This implementation calls {@code defaultAction}.
131 *
132 * @param b {@inheritDoc}
133 * @param p {@inheritDoc}
134 * @return the result of {@code defaultAction}
135 */
136 public R visitByte(byte b, P p) {
137 return defaultAction(b, p);
138 }
139
140 /**
141 * {@inheritDoc} This implementation calls {@code defaultAction}.
142 *
143 * @param c {@inheritDoc}
144 * @param p {@inheritDoc}
145 * @return the result of {@code defaultAction}
146 */
147 public R visitChar(char c, P p) {
148 return defaultAction(c, p);
149 }
150
151 /**
152 * {@inheritDoc} This implementation calls {@code defaultAction}.
153 *
154 * @param d {@inheritDoc}
155 * @param p {@inheritDoc}
156 * @return the result of {@code defaultAction}
157 */
158 public R visitDouble(double d, P p) {
159 return defaultAction(d, p);
160 }
161
162 /**
163 * {@inheritDoc} This implementation calls {@code defaultAction}.
164 *
165 * @param f {@inheritDoc}
166 * @param p {@inheritDoc}
167 * @return the result of {@code defaultAction}
168 */
169 public R visitFloat(float f, P p) {
170 return defaultAction(f, p);
171 }
172
173 /**
174 * {@inheritDoc} This implementation calls {@code defaultAction}.
175 *
176 * @param i {@inheritDoc}
177 * @param p {@inheritDoc}
178 * @return the result of {@code defaultAction}
179 */
180 public R visitInt(int i, P p) {
181 return defaultAction(i, p);
182 }
183
184 /**
185 * {@inheritDoc} This implementation calls {@code defaultAction}.
186 *
187 * @param i {@inheritDoc}
188 * @param p {@inheritDoc}
189 * @return the result of {@code defaultAction}
190 */
191 public R visitLong(long i, P p) {
192 return defaultAction(i, p);
193 }
194
195 /**
196 * {@inheritDoc} This implementation calls {@code defaultAction}.
197 *
198 * @param s {@inheritDoc}
199 * @param p {@inheritDoc}
200 * @return the result of {@code defaultAction}
201 */
202 public R visitShort(short s, P p) {
203 return defaultAction(s, p);
204 }
205
206 /**
207 * {@inheritDoc} This implementation calls {@code defaultAction}.
208 *
209 * @param s {@inheritDoc}
210 * @param p {@inheritDoc}
211 * @return the result of {@code defaultAction}
212 */
213 public R visitString(String s, P p) {
214 return defaultAction(s, p);
215 }
216
217 /**
218 * {@inheritDoc} This implementation calls {@code defaultAction}.
219 *
220 * @param t {@inheritDoc}
221 * @param p {@inheritDoc}
222 * @return the result of {@code defaultAction}
223 */
224 public R visitType(TypeMirror t, P p) {
225 return defaultAction(t, p);
226 }
227
228 /**
229 * {@inheritDoc} This implementation calls {@code defaultAction}.
230 *
231 * @param c {@inheritDoc}
232 * @param p {@inheritDoc}
233 * @return the result of {@code defaultAction}
234 */
235 public R visitEnumConstant(VariableElement c, P p) {
236 return defaultAction(c, p);
237 }
238
239 /**
240 * {@inheritDoc} This implementation calls {@code defaultAction}.
241 *
242 * @param a {@inheritDoc}
243 * @param p {@inheritDoc}
244 * @return the result of {@code defaultAction}
245 */
246 public R visitAnnotation(AnnotationMirror a, P p) {
247 return defaultAction(a, p);
248 }
249
250 /**
251 * {@inheritDoc} This implementation calls {@code defaultAction}.
252 *
253 * @param vals {@inheritDoc}
254 * @param p {@inheritDoc}
255 * @return the result of {@code defaultAction}
256 */
257 public R visitArray(List<? extends AnnotationValue> vals, P p) {
258 return defaultAction(vals, p);
259 }
260 }