1 /* 2 * Copyright (c) 2005, 2013, 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 * <p>Note that adding a default implementation of a new visit method 67 * in a visitor class will occur instead of adding a <em>default 68 * method</em> directly in the visitor interface since a Java SE 8 69 * language feature cannot be used to this version of the API since 70 * this version is required to be runnable on Java SE 7 71 * implementations. Future versions of the API that are only required 72 * to run on Java SE 8 and later may take advantage of default methods 73 * in this situation. 74 * 75 * @param <R> the return type of this visitor's methods 76 * @param <P> the type of the additional parameter to this visitor's methods. 77 * 78 * @author Joseph D. Darcy 79 * @author Scott Seligman 80 * @author Peter von der Ahé 81 * 82 * @see SimpleAnnotationValueVisitor7 83 * @see SimpleAnnotationValueVisitor8 84 * @since 1.6 85 */ 86 @SupportedSourceVersion(RELEASE_6) 87 public class SimpleAnnotationValueVisitor6<R, P> 88 extends AbstractAnnotationValueVisitor6<R, P> { 89 90 /** 91 * Default value to be returned; {@link #defaultAction 92 * defaultAction} returns this value unless the method is 93 * overridden. 94 */ 95 protected final R DEFAULT_VALUE; 96 97 /** 98 * Constructor for concrete subclasses; uses {@code null} for the 99 * default value. 100 */ 101 protected SimpleAnnotationValueVisitor6() { 102 super(); 103 DEFAULT_VALUE = null; 104 } 105 106 /** 107 * Constructor for concrete subclasses; uses the argument for the 108 * default value. 109 * 110 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE} 111 */ 112 protected SimpleAnnotationValueVisitor6(R defaultValue) { 113 super(); 114 DEFAULT_VALUE = defaultValue; 115 } 116 117 /** 118 * The default action for visit methods. The implementation in 119 * this class just returns {@link #DEFAULT_VALUE}; subclasses will 120 * commonly override this method. 121 * 122 * @param o the value of the annotation 123 * @param p a visitor-specified parameter 124 * @return {@code DEFAULT_VALUE} unless overridden 125 */ 126 protected R defaultAction(Object o, P p) { 127 return DEFAULT_VALUE; 128 } 129 130 /** 131 * {@inheritDoc} This implementation calls {@code defaultAction}. 132 * 133 * @param b {@inheritDoc} 134 * @param p {@inheritDoc} 135 * @return the result of {@code defaultAction} 136 */ 137 public R visitBoolean(boolean b, P p) { 138 return defaultAction(b, p); 139 } 140 141 /** 142 * {@inheritDoc} This implementation calls {@code defaultAction}. 143 * 144 * @param b {@inheritDoc} 145 * @param p {@inheritDoc} 146 * @return the result of {@code defaultAction} 147 */ 148 public R visitByte(byte b, P p) { 149 return defaultAction(b, p); 150 } 151 152 /** 153 * {@inheritDoc} This implementation calls {@code defaultAction}. 154 * 155 * @param c {@inheritDoc} 156 * @param p {@inheritDoc} 157 * @return the result of {@code defaultAction} 158 */ 159 public R visitChar(char c, P p) { 160 return defaultAction(c, p); 161 } 162 163 /** 164 * {@inheritDoc} This implementation calls {@code defaultAction}. 165 * 166 * @param d {@inheritDoc} 167 * @param p {@inheritDoc} 168 * @return the result of {@code defaultAction} 169 */ 170 public R visitDouble(double d, P p) { 171 return defaultAction(d, p); 172 } 173 174 /** 175 * {@inheritDoc} This implementation calls {@code defaultAction}. 176 * 177 * @param f {@inheritDoc} 178 * @param p {@inheritDoc} 179 * @return the result of {@code defaultAction} 180 */ 181 public R visitFloat(float f, P p) { 182 return defaultAction(f, p); 183 } 184 185 /** 186 * {@inheritDoc} This implementation calls {@code defaultAction}. 187 * 188 * @param i {@inheritDoc} 189 * @param p {@inheritDoc} 190 * @return the result of {@code defaultAction} 191 */ 192 public R visitInt(int i, P p) { 193 return defaultAction(i, p); 194 } 195 196 /** 197 * {@inheritDoc} This implementation calls {@code defaultAction}. 198 * 199 * @param i {@inheritDoc} 200 * @param p {@inheritDoc} 201 * @return the result of {@code defaultAction} 202 */ 203 public R visitLong(long i, P p) { 204 return defaultAction(i, p); 205 } 206 207 /** 208 * {@inheritDoc} This implementation calls {@code defaultAction}. 209 * 210 * @param s {@inheritDoc} 211 * @param p {@inheritDoc} 212 * @return the result of {@code defaultAction} 213 */ 214 public R visitShort(short s, P p) { 215 return defaultAction(s, p); 216 } 217 218 /** 219 * {@inheritDoc} This implementation calls {@code defaultAction}. 220 * 221 * @param s {@inheritDoc} 222 * @param p {@inheritDoc} 223 * @return the result of {@code defaultAction} 224 */ 225 public R visitString(String s, P p) { 226 return defaultAction(s, p); 227 } 228 229 /** 230 * {@inheritDoc} This implementation calls {@code defaultAction}. 231 * 232 * @param t {@inheritDoc} 233 * @param p {@inheritDoc} 234 * @return the result of {@code defaultAction} 235 */ 236 public R visitType(TypeMirror t, P p) { 237 return defaultAction(t, p); 238 } 239 240 /** 241 * {@inheritDoc} This implementation calls {@code defaultAction}. 242 * 243 * @param c {@inheritDoc} 244 * @param p {@inheritDoc} 245 * @return the result of {@code defaultAction} 246 */ 247 public R visitEnumConstant(VariableElement c, P p) { 248 return defaultAction(c, p); 249 } 250 251 /** 252 * {@inheritDoc} This implementation calls {@code defaultAction}. 253 * 254 * @param a {@inheritDoc} 255 * @param p {@inheritDoc} 256 * @return the result of {@code defaultAction} 257 */ 258 public R visitAnnotation(AnnotationMirror a, P p) { 259 return defaultAction(a, p); 260 } 261 262 /** 263 * {@inheritDoc} This implementation calls {@code defaultAction}. 264 * 265 * @param vals {@inheritDoc} 266 * @param p {@inheritDoc} 267 * @return the result of {@code defaultAction} 268 */ 269 public R visitArray(List<? extends AnnotationValue> vals, P p) { 270 return defaultAction(vals, p); 271 } 272 }