001/* AnnotatedElement.java 002 Copyright (C) 2004, 2005 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.lang.reflect; 040 041import 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 */ 065public 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}