001    /*
002     * Copyright 2004 Sun Microsystems, Inc.  All Rights Reserved.
003     * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004     *
005     * This code is free software; you can redistribute it and/or modify it
006     * under the terms of the GNU General Public License version 2 only, as
007     * published by the Free Software Foundation.  Sun designates this
008     * particular file as subject to the "Classpath" exception as provided
009     * by Sun in the LICENSE file that accompanied this code.
010     *
011     * This code is distributed in the hope that it will be useful, but WITHOUT
012     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013     * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
014     * version 2 for more details (a copy is included in the LICENSE file that
015     * accompanied this code).
016     *
017     * You should have received a copy of the GNU General Public License version
018     * 2 along with this work; if not, write to the Free Software Foundation,
019     * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020     *
021     * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022     * CA 95054 USA or visit www.sun.com if you need additional information or
023     * have any questions.
024     */
025    
026    package com.sun.mirror.declaration;
027    
028    
029    import java.lang.annotation.Annotation;
030    import java.util.Collection;
031    
032    import com.sun.mirror.type.*;
033    import com.sun.mirror.util.*;
034    
035    
036    /**
037     * Represents the declaration of a program element such as a package,
038     * class, or method.  Each declaration represents a static, language-level
039     * construct (and not, for example, a runtime construct of the virtual
040     * machine), and typically corresponds one-to-one with a particular
041     * fragment of source code.
042     *
043     * <p> Declarations should be compared using the {@link #equals(Object)}
044     * method.  There is no guarantee that any particular declaration will
045     * always be represented by the same object.
046     *
047     * @author Joseph D. Darcy
048     * @author Scott Seligman
049     *
050     * @see Declarations
051     * @see TypeMirror
052     * @since 1.5
053     */
054    
055    public interface Declaration {
056    
057        /**
058         * Tests whether an object represents the same declaration as this.
059         *
060         * @param obj  the object to be compared with this declaration
061         * @return <tt>true</tt> if the specified object represents the same
062         *          declaration as this
063         */
064        boolean equals(Object obj);
065    
066        /**
067         * Returns the text of the documentation ("javadoc") comment of
068         * this declaration.
069         *
070         * @return the documentation comment of this declaration, or <tt>null</tt>
071         *          if there is none
072         */
073        String getDocComment();
074    
075        /**
076         * Returns the annotations that are directly present on this declaration.
077         *
078         * @return the annotations directly present on this declaration;
079         *          an empty collection if there are none
080         */
081        Collection<AnnotationMirror> getAnnotationMirrors();
082    
083        /**
084         * Returns the annotation of this declaration having the specified
085         * type.  The annotation may be either inherited or directly
086         * present on this declaration.
087         *
088         * <p> The annotation returned by this method could contain an element
089         * whose value is of type <tt>Class</tt>.
090         * This value cannot be returned directly:  information necessary to
091         * locate and load a class (such as the class loader to use) is
092         * not available, and the class might not be loadable at all.
093         * Attempting to read a <tt>Class</tt> object by invoking the relevant
094         * method on the returned annotation
095         * will result in a {@link MirroredTypeException},
096         * from which the corresponding {@link TypeMirror} may be extracted.
097         * Similarly, attempting to read a <tt>Class[]</tt>-valued element
098         * will result in a {@link MirroredTypesException}.
099         *
100         * <blockquote>
101         * <i>Note:</i> This method is unlike
102         * others in this and related interfaces.  It operates on run-time
103         * reflective information -- representations of annotation types
104         * currently loaded into the VM -- rather than on the mirrored
105         * representations defined by and used throughout these
106         * interfaces.  It is intended for callers that are written to
107         * operate on a known, fixed set of annotation types.
108         * </blockquote>
109         *
110         * @param <A>  the annotation type
111         * @param annotationType  the <tt>Class</tt> object corresponding to
112         *          the annotation type
113         * @return the annotation of this declaration having the specified type
114         *
115         * @see #getAnnotationMirrors()
116         */
117        <A extends Annotation> A getAnnotation(Class<A> annotationType);
118    
119        /**
120         * Returns the modifiers of this declaration, excluding annotations.
121         * Implicit modifiers, such as the <tt>public</tt> and <tt>static</tt>
122         * modifiers of interface members, are included.
123         *
124         * @return the modifiers of this declaration in undefined order;
125         *          an empty collection if there are none
126         */
127        Collection<Modifier> getModifiers();
128    
129        /**
130         * Returns the simple (unqualified) name of this declaration.
131         * The name of a generic type does not include any reference
132         * to its formal type parameters.
133         * For example, the simple name of the interface declaration
134         * {@code java.util.Set<E>} is <tt>"Set"</tt>.
135         * If this declaration represents the empty package, an empty
136         * string is returned.
137         * If it represents a constructor, the simple name of its
138         * declaring class is returned.
139         *
140         * @return the simple name of this declaration
141         */
142        String getSimpleName();
143    
144        /**
145         * Returns the source position of the beginning of this declaration.
146         * Returns <tt>null</tt> if the position is unknown or not applicable.
147         *
148         * <p> This source position is intended for use in providing
149         * diagnostics, and indicates only approximately where a declaration
150         * begins.
151         *
152         * @return the source position of the beginning of this declaration,
153         *          or null if the position is unknown or not applicable
154         */
155        SourcePosition getPosition();
156    
157        /**
158         * Applies a visitor to this declaration.
159         *
160         * @param v the visitor operating on this declaration
161         */
162        void accept(DeclarationVisitor v);
163    }