1 /*
   2  * Copyright (c) 2010, 2014, 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 for annotation values with default behavior
  34  * appropriate for the {@link SourceVersion#RELEASE_7 RELEASE_7}
  35  * source version.  Visit methods call {@link #defaultAction
  36  * defaultAction} passing their arguments to {@code defaultAction}'s
  37  * corresponding parameters.
  38  *
  39  * <p> Methods in this class may be overridden subject to their
  40  * general contract.  Note that annotating methods in concrete
  41  * subclasses with {@link java.lang.Override @Override} will help
  42  * ensure that methods are overridden as intended.
  43  *
  44  * <p> <b>WARNING:</b> The {@code AnnotationValueVisitor} interface
  45  * implemented by this class may have methods added to it in the
  46  * future to accommodate new, currently unknown, language structures
  47  * added to future versions of the Java&trade; programming language.
  48  * Therefore, methods whose names begin with {@code "visit"} may be
  49  * added to this class in the future; to avoid incompatibilities,
  50  * classes which extend this class should not declare any instance
  51  * methods with names beginning with {@code "visit"}.
  52  *
  53  * <p>When such a new visit method is added, the default
  54  * implementation in this class will be to call the {@link
  55  * #visitUnknown visitUnknown} method.  A new simple annotation
  56  * value visitor class will also be introduced to correspond to the
  57  * new language level; this visitor will have different default
  58  * behavior for the visit method in question.  When the new visitor is
  59  * introduced, all or portions of this visitor may be deprecated.
  60  *
  61  * <p>Note that adding a default implementation of a new visit method
  62  * in a visitor class will occur instead of adding a <em>default
  63  * method</em> directly in the visitor interface since a Java SE 8
  64  * language feature cannot be used to this version of the API since
  65  * this version is required to be runnable on Java SE 7
  66  * implementations.  Future versions of the API that are only required
  67  * to run on Java SE 8 and later may take advantage of default methods
  68  * in this situation.
  69  *
  70  * @param <R> the return type of this visitor's methods
  71  * @param <P> the type of the additional parameter to this visitor's methods.
  72  *
  73  * @see SimpleAnnotationValueVisitor6
  74  * @see SimpleAnnotationValueVisitor8
  75  * @see SimpleAnnotationValueVisitor9
  76  * @since 1.7
  77  */
  78 @SuppressWarnings("deprecation") // Superclass deprecated
  79 @SupportedSourceVersion(RELEASE_7)
  80 public class SimpleAnnotationValueVisitor7<R, P> extends SimpleAnnotationValueVisitor6<R, P> {
  81     /**
  82      * Constructor for concrete subclasses; uses {@code null} for the
  83      * default value.
  84      */
  85     protected SimpleAnnotationValueVisitor7() {
  86         super(null);
  87     }
  88 
  89     /**
  90      * Constructor for concrete subclasses; uses the argument for the
  91      * default value.
  92      *
  93      * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
  94      */
  95     protected SimpleAnnotationValueVisitor7(R defaultValue) {
  96         super(defaultValue);
  97     }
  98 }