1 /* 2 * Copyright (c) 2011, 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 import javax.annotation.processing.SupportedSourceVersion; 29 import javax.lang.model.SourceVersion; 30 import static javax.lang.model.SourceVersion.*; 31 32 /** 33 * A simple visitor of program elements with default behavior 34 * appropriate for the {@link SourceVersion#RELEASE_8 RELEASE_8} 35 * source version. 36 * 37 * Visit methods corresponding to {@code RELEASE_7} and earlier 38 * language constructs call {@link #defaultAction defaultAction}, 39 * passing their arguments to {@code defaultAction}'s corresponding 40 * parameters. 41 * 42 * <p> Methods in this class may be overridden subject to their 43 * general contract. Note that annotating methods in concrete 44 * subclasses with {@link java.lang.Override @Override} will help 45 * ensure that methods are overridden as intended. 46 * 47 * <p> <b>WARNING:</b> The {@code ElementVisitor} interface 48 * implemented by this class may have methods added to it in the 49 * future to accommodate new, currently unknown, language structures 50 * added to future versions of the Java™ programming language. 51 * Therefore, methods whose names begin with {@code "visit"} may be 52 * added to this class in the future; to avoid incompatibilities, 53 * classes which extend this class should not declare any instance 54 * methods with names beginning with {@code "visit"}. 55 * 56 * <p>When such a new visit method is added, the default 57 * implementation in this class will be to call the {@link 58 * #visitUnknown visitUnknown} method. A new simple element visitor 59 * class will also be introduced to correspond to the new language 60 * level; this visitor will have different default behavior for the 61 * visit method in question. When the new visitor is introduced, all 62 * or portions of this visitor may be deprecated. 63 * 64 * <p>Note that adding a default implementation of a new visit method 65 * in a visitor class will occur instead of adding a <em>default 66 * method</em> directly in the visitor interface since a Java SE 8 67 * language feature cannot be used to this version of the API since 68 * this version is required to be runnable on Java SE 7 69 * implementations. Future versions of the API that are only required 70 * to run on Java SE 8 and later may take advantage of default methods 71 * in this situation. 72 * 73 * @param <R> the return type of this visitor's methods. Use {@code Void} 74 * for visitors that do not need to return results. 75 * @param <P> the type of the additional parameter to this visitor's methods. Use {@code Void} 76 * for visitors that do not need an additional parameter. 77 * 78 * @see SimpleElementVisitor6 79 * @see SimpleElementVisitor7 80 * @since 1.8 81 */ 82 @SupportedSourceVersion(RELEASE_8) 83 public class SimpleElementVisitor8<R, P> extends SimpleElementVisitor7<R, P> { 84 /** 85 * Constructor for concrete subclasses; uses {@code null} for the 86 * default value. 87 */ 88 protected SimpleElementVisitor8(){ 89 super(null); 90 } 91 92 /** 93 * Constructor for concrete subclasses; uses the argument for the 94 * default value. 95 * 96 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE} 97 */ 98 protected SimpleElementVisitor8(R defaultValue){ 99 super(defaultValue); 100 } 101 }