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 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 * @param <R> the return type of this visitor's methods. Use {@link 57 * Void} for visitors that do not need to return results. 58 * @param <P> the type of the additional parameter to this visitor's 59 * methods. Use {@code Void} for visitors that do not need an 60 * additional parameter. 61 * 62 * @author Joseph D. Darcy 63 * @author Scott Seligman 64 * @author Peter von der Ahé 65 * 66 * @see AbstractElementVisitor7 67 * @see AbstractElementVisitor8 68 * @see AbstractElementVisitor9 69 * @see AbstractElementVisitor14 70 * @since 1.6 71 */ 72 @SupportedSourceVersion(RELEASE_6) 73 public abstract class AbstractElementVisitor6<R, P> implements ElementVisitor<R, P> { 74 /** 75 * Constructor for concrete subclasses to call. 76 * @deprecated Release 6 is obsolete; update to a visitor for a newer 77 * release level. 78 */ 79 @Deprecated(since="9") 80 protected AbstractElementVisitor6(){} 81 82 /** 83 * Visits any program element as if by passing itself to that 84 * element's {@link Element#accept accept} method. The invocation 85 * {@code v.visit(elem, p)} is equivalent to {@code elem.accept(v, 86 * p)}. 87 * 88 * @param e the element to visit 89 * @param p a visitor-specified parameter 90 * @return a visitor-specified result 91 */ 92 public final R visit(Element e, P p) { 93 return e.accept(this, p); 94 } 95 96 /** 97 * Visits any program element as if by passing itself to that 98 * element's {@link Element#accept accept} method and passing 99 * {@code null} for the additional parameter. The invocation 100 * {@code v.visit(elem)} is equivalent to {@code elem.accept(v, 101 * null)}. 102 * 103 * @param e the element to visit 104 * @return a visitor-specified result 105 */ 106 public final R visit(Element e) { 107 return e.accept(this, null); 108 } 109 110 /** 111 * {@inheritDoc} 112 * 113 * @implSpec The default implementation of this method in 114 * {@code AbstractElementVisitor6} will always throw 115 * {@code new UnknownElementException(e, p)}. 116 * This behavior is not required of a subclass. 117 * 118 * @param e {@inheritDoc} 119 * @param p {@inheritDoc} 120 * @return {@inheritDoc} 121 * @throws UnknownElementException 122 * a visitor implementation may optionally throw this exception 123 */ 124 @Override 125 public R visitUnknown(Element e, P p) { 126 throw new UnknownElementException(e, p); 127 } 128 129 /** 130 * {@inheritDoc} 131 * 132 * @implSpec Visits a {@code ModuleElement} by calling {@code 133 * visitUnknown}. 134 * 135 * @param e {@inheritDoc} 136 * @param p {@inheritDoc} 137 * @return {@inheritDoc} 138 * 139 * @since 9 140 * @spec JPMS 141 */ 142 @Override 143 public R visitModule(ModuleElement e, P p) { 144 // Use implementation from interface default method 145 return ElementVisitor.super.visitModule(e, p); 146 } 147 148 /** 149 * {@inheritDoc} 150 * 151 * @implSpec Visits a {@code RecordComponentElement} by calling {@code 152 * visitUnknown}. 153 * 154 * @param e {@inheritDoc} 155 * @param p {@inheritDoc} 156 * @return {@inheritDoc} 157 * 158 * @since 14 159 */ 160 @SuppressWarnings("removal") 161 @Override 162 public R visitRecordComponent(RecordComponentElement e, P p) { 163 // Use implementation from interface default method 164 return ElementVisitor.super.visitRecordComponent(e, p); 165 } 166 }