SimpleTypeVisitor6.java revision 3884:b6960e2da008
1/* 2 * Copyright (c) 2005, 2017, 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 26package javax.lang.model.util; 27 28import javax.lang.model.type.*; 29import javax.annotation.processing.SupportedSourceVersion; 30import javax.lang.model.SourceVersion; 31import static javax.lang.model.SourceVersion.*; 32 33 34/** 35 * A simple visitor of types with default behavior appropriate for the 36 * {@link SourceVersion#RELEASE_6 RELEASE_6} source version. 37 * 38 * Visit methods corresponding to {@code RELEASE_6} language 39 * constructs call {@link #defaultAction defaultAction}, passing their 40 * arguments to {@code defaultAction}'s corresponding parameters. 41 * 42 * For constructs introduced in {@code RELEASE_7} and later, {@code 43 * visitUnknown} is called instead. 44 * 45 * <p> Methods in this class may be overridden subject to their 46 * general contract. Note that annotating methods in concrete 47 * subclasses with {@link java.lang.Override @Override} will help 48 * ensure that methods are overridden as intended. 49 * 50 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented 51 * by this class may have methods added to it in the future to 52 * accommodate new, currently unknown, language structures added to 53 * future versions of the Java™ programming language. 54 * Therefore, methods whose names begin with {@code "visit"} may be 55 * added to this class in the future; to avoid incompatibilities, 56 * classes which extend this class should not declare any instance 57 * methods with names beginning with {@code "visit"}. 58 * 59 * <p>When such a new visit method is added, the default 60 * implementation in this class will be to call the {@link 61 * #visitUnknown visitUnknown} method. A new simple type visitor 62 * class will also be introduced to correspond to the new language 63 * level; this visitor will have different default behavior for the 64 * visit method in question. When the new visitor is introduced, all 65 * or portions of this visitor may be deprecated. 66 * 67 * @param <R> the return type of this visitor's methods. Use {@link 68 * Void} for visitors that do not need to return results. 69 * @param <P> the type of the additional parameter to this visitor's 70 * methods. Use {@code Void} for visitors that do not need an 71 * additional parameter. 72 * 73 * @author Joseph D. Darcy 74 * @author Scott Seligman 75 * @author Peter von der Ahé 76 * 77 * @see SimpleTypeVisitor7 78 * @see SimpleTypeVisitor8 79 * @see SimpleTypeVisitor9 80 * @since 1.6 81 * @deprecated Release 6 is obsolete; update to a visitor for a newer 82 * release level. 83 */ 84@Deprecated 85@SupportedSourceVersion(RELEASE_6) 86public class SimpleTypeVisitor6<R, P> extends AbstractTypeVisitor6<R, P> { 87 /** 88 * Default value to be returned; {@link #defaultAction 89 * defaultAction} returns this value unless the method is 90 * overridden. 91 */ 92 protected final R DEFAULT_VALUE; 93 94 /** 95 * Constructor for concrete subclasses; uses {@code null} for the 96 * default value. 97 */ 98 protected SimpleTypeVisitor6(){ 99 DEFAULT_VALUE = null; 100 } 101 102 /** 103 * Constructor for concrete subclasses; uses the argument for the 104 * default value. 105 * 106 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE} 107 */ 108 protected SimpleTypeVisitor6(R defaultValue){ 109 DEFAULT_VALUE = defaultValue; 110 } 111 112 /** 113 * The default action for visit methods. The implementation in 114 * this class just returns {@link #DEFAULT_VALUE}; subclasses will 115 * commonly override this method. 116 * 117 * @param e the type to process 118 * @param p a visitor-specified parameter 119 * @return {@code DEFAULT_VALUE} unless overridden 120 */ 121 protected R defaultAction(TypeMirror e, P p) { 122 return DEFAULT_VALUE; 123 } 124 125 /** 126 * {@inheritDoc} This implementation calls {@code defaultAction}. 127 * 128 * @param t {@inheritDoc} 129 * @param p {@inheritDoc} 130 * @return the result of {@code defaultAction} 131 */ 132 public R visitPrimitive(PrimitiveType t, P p) { 133 return defaultAction(t, p); 134 } 135 136 /** 137 * {@inheritDoc} This implementation calls {@code defaultAction}. 138 * 139 * @param t {@inheritDoc} 140 * @param p {@inheritDoc} 141 * @return the result of {@code defaultAction} 142 */ 143 public R visitNull(NullType t, P p){ 144 return defaultAction(t, p); 145 } 146 147 /** 148 * {@inheritDoc} This implementation calls {@code defaultAction}. 149 * 150 * @param t {@inheritDoc} 151 * @param p {@inheritDoc} 152 * @return the result of {@code defaultAction} 153 */ 154 public R visitArray(ArrayType t, P p){ 155 return defaultAction(t, p); 156 } 157 158 /** 159 * {@inheritDoc} This implementation calls {@code defaultAction}. 160 * 161 * @param t {@inheritDoc} 162 * @param p {@inheritDoc} 163 * @return the result of {@code defaultAction} 164 */ 165 public R visitDeclared(DeclaredType t, P p){ 166 return defaultAction(t, p); 167 } 168 169 /** 170 * {@inheritDoc} This implementation calls {@code defaultAction}. 171 * 172 * @param t {@inheritDoc} 173 * @param p {@inheritDoc} 174 * @return the result of {@code defaultAction} 175 */ 176 public R visitError(ErrorType t, P p){ 177 return defaultAction(t, p); 178 } 179 180 /** 181 * {@inheritDoc} This implementation calls {@code defaultAction}. 182 * 183 * @param t {@inheritDoc} 184 * @param p {@inheritDoc} 185 * @return the result of {@code defaultAction} 186 */ 187 public R visitTypeVariable(TypeVariable t, P p){ 188 return defaultAction(t, p); 189 } 190 191 /** 192 * {@inheritDoc} This implementation calls {@code defaultAction}. 193 * 194 * @param t {@inheritDoc} 195 * @param p {@inheritDoc} 196 * @return the result of {@code defaultAction} 197 */ 198 public R visitWildcard(WildcardType t, P p){ 199 return defaultAction(t, p); 200 } 201 202 /** 203 * {@inheritDoc} This implementation calls {@code defaultAction}. 204 * 205 * @param t {@inheritDoc} 206 * @param p {@inheritDoc} 207 * @return the result of {@code defaultAction} 208 */ 209 public R visitExecutable(ExecutableType t, P p) { 210 return defaultAction(t, p); 211 } 212 213 /** 214 * {@inheritDoc} This implementation calls {@code defaultAction}. 215 * 216 * @param t {@inheritDoc} 217 * @param p {@inheritDoc} 218 * @return the result of {@code defaultAction} 219 */ 220 public R visitNoType(NoType t, P p){ 221 return defaultAction(t, p); 222 } 223} 224