001 /* AnnotatedElement.java 002 Copyright (C) 2004, 2005 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package java.lang.reflect; 040 041 import java.lang.annotation.Annotation; 042 043 /** 044 * <p> 045 * Represents an element that can be annotated. The methods of this interface 046 * provide reflection-based access to the annotations associated with a 047 * particular element, such as a class, field, method or package. Each 048 * annotation returned by these methods is both immutable and serializable. 049 * The returned arrays may be freely modified, without any effect on the 050 * arrays returned to future callers. 051 * </p> 052 * <p> 053 * If an annotation refers to a type or enumeration constant that is 054 * inaccessible, then a <code>TypeNotPresentException</code> or 055 * <code>EnumConstantNotPresentException</code> will be thrown. Likewise, 056 * invalid annotations will produce either a 057 * <code>AnnotationTypeMismatchException</code> or 058 * <code>IncompleteAnnotationException</code>. 059 * </p> 060 * 061 * @author Tom Tromey (tromey@redhat.com) 062 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 063 * @since 1.5 064 */ 065 public interface AnnotatedElement 066 { 067 068 /** 069 * Returns the element's annotation for the specified annotation type, 070 * or <code>null</code> if no such annotation exists. 071 * 072 * @param annotationClass the type of annotation to look for. 073 * @return this element's annotation for the specified type, or 074 * <code>null</code> if no such annotation exists. 075 * @throws NullPointerException if the annotation class is <code>null</code>. 076 */ 077 <T extends Annotation> T getAnnotation(Class<T> annotationClass); 078 079 /** 080 * Returns all annotations associated with the element. If there are 081 * no annotations associated with the element, then a zero-length array 082 * will be returned. The returned array may be modified by the client 083 * code, but this will have no effect on the annotation content of the 084 * element, and hence no effect on the return value of this method for 085 * future callers. 086 * 087 * @return this element's annotations. 088 */ 089 Annotation[] getAnnotations(); 090 091 /** 092 * Returns all annotations directly defined by the element. If there are 093 * no annotations directly associated with the element, then a zero-length 094 * array will be returned. The returned array may be modified by the client 095 * code, but this will have no effect on the annotation content of this 096 * class, and hence no effect on the return value of this method for 097 * future callers. 098 * 099 * @return the annotations directly defined by the element. 100 * @since 1.5 101 */ 102 Annotation[] getDeclaredAnnotations(); 103 104 /** 105 * Returns true if an annotation for the specified type is associated 106 * with the element. This is primarily a short-hand for using marker 107 * annotations. 108 * 109 * @param annotationClass the type of annotation to look for. 110 * @return true if an annotation exists for the specified type. 111 * @since 1.5 112 */ 113 boolean isAnnotationPresent(Class<? extends Annotation> annotationClass); 114 115 }