1   /*
    2    * Copyright (c) 2005, 2006, 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.element;
   27   
   28   
   29   import java.util.List;
   30   import javax.lang.model.type;
   31   
   32   /**
   33    * Represents a value of an annotation type element.
   34    * A value is of one of the following types:
   35    * <ul><li> a wrapper class (such as {@link Integer}) for a primitive type
   36    *     <li> {@code String}
   37    *     <li> {@code TypeMirror}
   38    *     <li> {@code VariableElement} (representing an enum constant)
   39    *     <li> {@code AnnotationMirror}
   40    *     <li> {@code List<? extends AnnotationValue>}
   41    *              (representing the elements, in declared order, if the value is an array)
   42    * </ul>
   43    *
   44    * @author Joseph D. Darcy
   45    * @author Scott Seligman
   46    * @author Peter von der Ah&eacute;
   47    * @since 1.6
   48    */
   49   public interface AnnotationValue {
   50   
   51       /**
   52        * Returns the value.
   53        *
   54        * @return the value
   55        */
   56       Object getValue();
   57   
   58       /**
   59        * Returns a string representation of this value.
   60        * This is returned in a form suitable for representing this value
   61        * in the source code of an annotation.
   62        *
   63        * @return a string representation of this value
   64        */
   65       String toString();
   66   
   67       /**
   68        * Applies a visitor to this value.
   69        *
   70        * @param <R> the return type of the visitor's methods
   71        * @param <P> the type of the additional parameter to the visitor's methods
   72        * @param v   the visitor operating on this value
   73        * @param p   additional parameter to the visitor
   74        * @return a visitor-specified result
   75        */
   76       <R, P> R accept(AnnotationValueVisitor<R, P> v, P p);
   77   }