1 /*

     2  * Copyright (c) 2011, 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.ModuleElement;

    31 import static javax.lang.model.SourceVersion.*;

    32 

    33 /**

    34  * A simple visitor of program elements with default behavior

    35  * appropriate for the {@link SourceVersion#RELEASE_9 RELEASE_9}

    36  * source version.

    37  *

    38  * Visit methods corresponding to {@code RELEASE_9} and earlier

    39  * language constructs call {@link #defaultAction defaultAction},

    40  * passing their arguments to {@code defaultAction}'s corresponding

    41  * parameters.

    42  *

    43  * <p> Methods in this class may be overridden subject to their

    44  * general contract.  Note that annotating methods in concrete

    45  * subclasses with {@link java.lang.Override @Override} will help

    46  * ensure that methods are overridden as intended.

    47  *

    48  * <p> <b>WARNING:</b> The {@code ElementVisitor} interface

    49  * implemented by this class may have methods added to it in the

    50  * future to accommodate new, currently unknown, language structures

    51  * added to future versions of the Java™ programming language.

    52  * Therefore, methods whose names begin with {@code "visit"} may be

    53  * added to this class in the future; to avoid incompatibilities,

    54  * classes which extend this class should not declare any instance

    55  * methods with names beginning with {@code "visit"}.

    56  *

    57  * <p>When such a new visit method is added, the default

    58  * implementation in this class will be to call the {@link

    59  * #visitUnknown visitUnknown} method.  A new simple element visitor

    60  * class will also be introduced to correspond to the new language

    61  * level; this visitor will have different default behavior for the

    62  * visit method in question.  When the new visitor is introduced, all

    63  * or portions of this visitor may be deprecated.

    64  *

    65  * @param <R> the return type of this visitor's methods.  Use {@code Void}

    66  *             for visitors that do not need to return results.

    67  * @param <P> the type of the additional parameter to this visitor's methods.  Use {@code Void}

    68  *              for visitors that do not need an additional parameter.

    69  *

    70  * @see SimpleElementVisitor6

    71  * @see SimpleElementVisitor7

    72  * @see SimpleElementVisitor8

    73  * @since 9

    74  * @spec JPMS

    75  */

    76 @SupportedSourceVersion(RELEASE_9)

    77 public class SimpleElementVisitor9<R, P> extends SimpleElementVisitor8<R, P> {

    78     /**

    79      * Constructor for concrete subclasses; uses {@code null} for the

    80      * default value.

    81      */

    82     protected SimpleElementVisitor9(){

    83         super(null);

    84     }

    85 

    86     /**

    87      * Constructor for concrete subclasses; uses the argument for the

    88      * default value.

    89      *

    90      * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

    91      */

    92     protected SimpleElementVisitor9(R defaultValue){

    93         super(defaultValue);

    94     }

    95 

    96     /**

    97      * Visits a {@code ModuleElement} by calling {@code

    98      * defaultAction}.

    99      *

   100      * @param e the element to visit

   101      * @param p a visitor-specified parameter

   102      * @return  the result of {@code defaultAction}

   103      */

   104     @Override

   105     public R visitModule(ModuleElement e, P p) {

   106         return defaultAction(e, p);

   107     }

   108 }