1 /* 2 * Copyright (c) 2005, 2015, 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 import javax.annotation.processing.SupportedSourceVersion; 29 import javax.lang.model.SourceVersion; 30 import javax.lang.model.element.*; 31 import static javax.lang.model.SourceVersion.*; 32 33 34 /** 35 * A skeletal visitor of program elements with default behavior 36 * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6} 37 * source version. 38 * 39 * <p> <b>WARNING:</b> The {@code ElementVisitor} interface 40 * implemented by this class may have methods added to it in the 41 * future to accommodate new, currently unknown, language structures 42 * added to future versions of the Java™ programming language. 43 * Therefore, methods whose names begin with {@code "visit"} may be 44 * added to this class in the future; to avoid incompatibilities, 45 * classes which extend this class should not declare any instance 46 * methods with names beginning with {@code "visit"}. 47 * 48 * <p>When such a new visit method is added, the default 49 * implementation in this class will be to call the {@link 50 * #visitUnknown visitUnknown} method. A new abstract element visitor 51 * class will also be introduced to correspond to the new language 52 * level; this visitor will have different default behavior for the 53 * visit method in question. When the new visitor is introduced, all 54 * or portions of this visitor may be deprecated. 55 * 56 * <p>Note that adding a default implementation of a new visit method 57 * in a visitor class will occur instead of adding a <em>default 58 * method</em> directly in the visitor interface since a Java SE 8 59 * language feature cannot be used to this version of the API since 60 * this version is required to be runnable on Java SE 7 61 * implementations. Future versions of the API that are only required 62 * to run on Java SE 8 and later may take advantage of default methods 63 * in this situation. 64 * 65 * @param <R> the return type of this visitor's methods. Use {@link 66 * Void} for visitors that do not need to return results. 67 * @param <P> the type of the additional parameter to this visitor's 68 * methods. Use {@code Void} for visitors that do not need an 69 * additional parameter. 70 * 71 * @author Joseph D. Darcy 72 * @author Scott Seligman 73 * @author Peter von der Ahé 74 * 75 * @see AbstractElementVisitor7 76 * @see AbstractElementVisitor8 77 * @see AbstractElementVisitor9 78 * @since 1.6 79 * @deprecated Release 6 is obsolete; update to a visitor for a newer 80 * release level. 81 */ 82 @Deprecated 83 @SupportedSourceVersion(RELEASE_6) 84 public abstract class AbstractElementVisitor6<R, P> implements ElementVisitor<R, P> { 85 /** 86 * Constructor for concrete subclasses to call. 87 */ 88 protected AbstractElementVisitor6(){} 89 90 /** 91 * Visits any program element as if by passing itself to that 92 * element's {@link Element#accept accept} method. The invocation 93 * {@code v.visit(elem)} is equivalent to {@code elem.accept(v, 94 * p)}. 95 * 96 * @param e the element to visit 97 * @param p a visitor-specified parameter 98 * @return a visitor-specified result 99 */ 100 public final R visit(Element e, P p) { 101 return e.accept(this, p); 102 } 103 104 /** 105 * Visits any program element as if by passing itself to that 106 * element's {@link Element#accept accept} method and passing 107 * {@code null} for the additional parameter. The invocation 108 * {@code v.visit(elem)} is equivalent to {@code elem.accept(v, 109 * null)}. 110 * 111 * @param e the element to visit 112 * @return a visitor-specified result 113 */ 114 public final R visit(Element e) { 115 return e.accept(this, null); 116 } 117 118 /** 119 * {@inheritDoc} 120 * 121 * <p> The default implementation of this method in 122 * {@code AbstractElementVisitor6} will always throw 123 * {@code UnknownElementException}. 124 * This behavior is not required of a subclass. 125 * 126 * @param e the element to visit 127 * @param p a visitor-specified parameter 128 * @return a visitor-specified result 129 * @throws UnknownElementException 130 * a visitor implementation may optionally throw this exception 131 */ 132 public R visitUnknown(Element e, P p) { 133 throw new UnknownElementException(e, p); 134 } 135 136 /** 137 * Visits a {@code ModuleElement} by calling {@code 138 * visitUnknown}. 139 140 * @param e {@inheritDoc} 141 * @param p {@inheritDoc} 142 * @return the result of {@code visitUnknown} 143 * 144 * @since 9 145 */ 146 @Override 147 public R visitModule(ModuleElement e, P p) { 148 return visitUnknown(e, p); 149 } 150 }