1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/javax/lang/model/element/Element.java Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,258 @@
1.4 +/*
1.5 + * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Sun designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Sun in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.25 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.26 + * have any questions.
1.27 + */
1.28 +
1.29 +package javax.lang.model.element;
1.30 +
1.31 +
1.32 +import java.lang.annotation.Annotation;
1.33 +import java.lang.annotation.AnnotationTypeMismatchException;
1.34 +import java.lang.annotation.IncompleteAnnotationException;
1.35 +import java.util.List;
1.36 +import java.util.Set;
1.37 +
1.38 +import javax.lang.model.element.Modifier;
1.39 +import javax.lang.model.type.*;
1.40 +import javax.lang.model.util.*;
1.41 +
1.42 +
1.43 +/**
1.44 + * Represents a program element such as a package, class, or method.
1.45 + * Each element represents a static, language-level construct
1.46 + * (and not, for example, a runtime construct of the virtual machine).
1.47 + *
1.48 + * <p> Elements should be compared using the {@link #equals(Object)}
1.49 + * method. There is no guarantee that any particular element will
1.50 + * always be represented by the same object.
1.51 + *
1.52 + * <p> To implement operations based on the class of an {@code
1.53 + * Element} object, either use a {@linkplain ElementVisitor visitor} or
1.54 + * use the result of the {@link #getKind} method. Using {@code
1.55 + * instanceof} is <em>not</em> necessarily a reliable idiom for
1.56 + * determining the effective class of an object in this modeling
1.57 + * hierarchy since an implementation may choose to have a single object
1.58 + * implement multiple {@code Element} subinterfaces.
1.59 + *
1.60 + * @author Joseph D. Darcy
1.61 + * @author Scott Seligman
1.62 + * @author Peter von der Ahé
1.63 + * @see Elements
1.64 + * @see TypeMirror
1.65 + * @since 1.6
1.66 + */
1.67 +public interface Element {
1.68 +
1.69 + /**
1.70 + * Returns the type defined by this element.
1.71 + *
1.72 + * <p> A generic element defines a family of types, not just one.
1.73 + * If this is a generic element, a <i>prototypical</i> type is
1.74 + * returned. This is the element's invocation on the
1.75 + * type variables corresponding to its own formal type parameters.
1.76 + * For example,
1.77 + * for the generic class element {@code C<N extends Number>},
1.78 + * the parameterized type {@code C<N>} is returned.
1.79 + * The {@link Types} utility interface has more general methods
1.80 + * for obtaining the full range of types defined by an element.
1.81 + *
1.82 + * @see Types
1.83 + *
1.84 + * @return the type defined by this element
1.85 + */
1.86 + TypeMirror asType();
1.87 +
1.88 + /**
1.89 + * Returns the {@code kind} of this element.
1.90 + *
1.91 + * @return the kind of this element
1.92 + */
1.93 + ElementKind getKind();
1.94 +
1.95 + /**
1.96 + * Returns the annotations that are directly present on this element.
1.97 + *
1.98 + * <p> To get inherited annotations as well, use
1.99 + * {@link Elements#getAllAnnotationMirrors(Element) getAllAnnotationMirrors}.
1.100 + *
1.101 + * @see ElementFilter
1.102 + *
1.103 + * @return the annotations directly present on this element;
1.104 + * an empty list if there are none
1.105 + */
1.106 + List<? extends AnnotationMirror> getAnnotationMirrors();
1.107 +
1.108 + /**
1.109 + * Returns this element's annotation for the specified type if
1.110 + * such an annotation is present, else {@code null}. The
1.111 + * annotation may be either inherited or directly present on this
1.112 + * element.
1.113 + *
1.114 + * <p> The annotation returned by this method could contain an element
1.115 + * whose value is of type {@code Class}.
1.116 + * This value cannot be returned directly: information necessary to
1.117 + * locate and load a class (such as the class loader to use) is
1.118 + * not available, and the class might not be loadable at all.
1.119 + * Attempting to read a {@code Class} object by invoking the relevant
1.120 + * method on the returned annotation
1.121 + * will result in a {@link MirroredTypeException},
1.122 + * from which the corresponding {@link TypeMirror} may be extracted.
1.123 + * Similarly, attempting to read a {@code Class[]}-valued element
1.124 + * will result in a {@link MirroredTypesException}.
1.125 + *
1.126 + * <blockquote>
1.127 + * <i>Note:</i> This method is unlike others in this and related
1.128 + * interfaces. It operates on runtime reflective information —
1.129 + * representations of annotation types currently loaded into the
1.130 + * VM — rather than on the representations defined by and used
1.131 + * throughout these interfaces. Consequently, calling methods on
1.132 + * the returned annotation object can throw many of the exceptions
1.133 + * that can be thrown when calling methods on an annotation object
1.134 + * returned by core reflection. This method is intended for
1.135 + * callers that are written to operate on a known, fixed set of
1.136 + * annotation types.
1.137 + * </blockquote>
1.138 + *
1.139 + * @param <A> the annotation type
1.140 + * @param annotationType the {@code Class} object corresponding to
1.141 + * the annotation type
1.142 + * @return this element's annotation for the specified annotation
1.143 + * type if present on this element, else {@code null}
1.144 + *
1.145 + * @see #getAnnotationMirrors()
1.146 + * @see java.lang.reflect.AnnotatedElement#getAnnotation
1.147 + * @see EnumConstantNotPresentException
1.148 + * @see AnnotationTypeMismatchException
1.149 + * @see IncompleteAnnotationException
1.150 + * @see MirroredTypeException
1.151 + * @see MirroredTypesException
1.152 + */
1.153 + <A extends Annotation> A getAnnotation(Class<A> annotationType);
1.154 +
1.155 + /**
1.156 + * Returns the modifiers of this element, excluding annotations.
1.157 + * Implicit modifiers, such as the {@code public} and {@code static}
1.158 + * modifiers of interface members, are included.
1.159 + *
1.160 + * @return the modifiers of this element, or an empty set if there are none
1.161 + */
1.162 + Set<Modifier> getModifiers();
1.163 +
1.164 + /**
1.165 + * Returns the simple (unqualified) name of this element.
1.166 + * The name of a generic type does not include any reference
1.167 + * to its formal type parameters.
1.168 + * For example, the simple name of the type element
1.169 + * {@code java.util.Set<E>} is {@code "Set"}.
1.170 + * If this element represents an unnamed package, an empty name is
1.171 + * returned. If it represents a constructor, the name "{@code
1.172 + * <init>}" is returned. If it represents a static initializer,
1.173 + * the name "{@code <clinit>}" is returned. If it represents an
1.174 + * anonymous class or instance initializer, an empty name is
1.175 + * returned.
1.176 + *
1.177 + * @return the simple name of this element
1.178 + */
1.179 + Name getSimpleName();
1.180 +
1.181 + /**
1.182 + * Returns the innermost element
1.183 + * within which this element is, loosely speaking, enclosed.
1.184 + * <ul>
1.185 + * <li> If this element is one whose declaration is lexically enclosed
1.186 + * immediately within the declaration of another element, that other
1.187 + * element is returned.
1.188 + * <li> If this is a top-level type, its package is returned.
1.189 + * <li> If this is a package, {@code null} is returned.
1.190 + * <li> If this is a type parameter, {@code null} is returned.
1.191 + * </ul>
1.192 + *
1.193 + * @return the enclosing element, or {@code null} if there is none
1.194 + * @see Elements#getPackageOf
1.195 + */
1.196 + Element getEnclosingElement();
1.197 +
1.198 + /**
1.199 + * Returns the elements that are, loosely speaking, directly
1.200 + * enclosed by this element.
1.201 + *
1.202 + * A class or interface is considered to enclose the fields,
1.203 + * methods, constructors, and member types that it directly
1.204 + * declares. This includes any (implicit) default constructor and
1.205 + * the implicit {@code values} and {@code valueOf} methods of an
1.206 + * enum type.
1.207 + *
1.208 + * A package encloses the top-level classes and interfaces within
1.209 + * it, but is not considered to enclose subpackages.
1.210 + *
1.211 + * Other kinds of elements are not currently considered to enclose
1.212 + * any elements; however, that may change as this API or the
1.213 + * programming language evolves.
1.214 + *
1.215 + * <p>Note that elements of certain kinds can be isolated using
1.216 + * methods in {@link ElementFilter}.
1.217 + *
1.218 + * @return the enclosed elements, or an empty list if none
1.219 + * @see Elements#getAllMembers
1.220 + * @jls3 8.8.9 Default Constructor
1.221 + * @jls3 8.9 Enums
1.222 + */
1.223 + List<? extends Element> getEnclosedElements();
1.224 +
1.225 + /**
1.226 + * Returns {@code true} if the argument represents the same
1.227 + * element as {@code this}, or {@code false} otherwise.
1.228 + *
1.229 + * <p>Note that the identity of an element involves implicit state
1.230 + * not directly accessible from the element's methods, including
1.231 + * state about the presence of unrelated types. Element objects
1.232 + * created by different implementations of these interfaces should
1.233 + * <i>not</i> be expected to be equal even if "the same"
1.234 + * element is being modeled; this is analogous to the inequality
1.235 + * of {@code Class} objects for the same class file loaded through
1.236 + * different class loaders.
1.237 + *
1.238 + * @param obj the object to be compared with this element
1.239 + * @return {@code true} if the specified object represents the same
1.240 + * element as this
1.241 + */
1.242 + boolean equals(Object obj);
1.243 +
1.244 + /**
1.245 + * Obeys the general contract of {@link Object#hashCode Object.hashCode}.
1.246 + *
1.247 + * @see #equals
1.248 + */
1.249 + int hashCode();
1.250 +
1.251 + /**
1.252 + * Applies a visitor to this element.
1.253 + *
1.254 + * @param <R> the return type of the visitor's methods
1.255 + * @param <P> the type of the additional parameter to the visitor's methods
1.256 + * @param v the visitor operating on this element
1.257 + * @param p additional parameter to the visitor
1.258 + * @return a visitor-specified result
1.259 + */
1.260 + <R, P> R accept(ElementVisitor<R, P> v, P p);
1.261 +}
