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Diffstat (limited to 'javax/lang/model/element/Element.java')
-rw-r--r-- | javax/lang/model/element/Element.java | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/javax/lang/model/element/Element.java b/javax/lang/model/element/Element.java new file mode 100644 index 000000000..507547600 --- /dev/null +++ b/javax/lang/model/element/Element.java @@ -0,0 +1,213 @@ +/* Element.java -- Represents a program element at the language level. + Copyright (C) 2012 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package javax.lang.model.element; + +import java.lang.annotation.Annotation; + +import java.util.List; +import java.util.Set; + +import javax.lang.model.type.TypeMirror; + +/** + * <p> + * Represents a program element at the language level. For example, + * an {@code Element} may represent a package, a class or a type + * parameter. Types only present at runtime in the virtual machine + * are not represented. + * </p> + * <p>To compare two instances, use {@link #equals(Object)} as there + * is no guarantee that == will hold. To determine the subtype of + * {@code Element}, use {@link #getKind()} or a visitor, as + * implementations may use the same class to implement multiple + * subinterfaces.</p> + * + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @since 1.6 + */ +public interface Element +{ + + /** + * Applies a visitor to this element. + * + * @param <R> the return type of the visitor's methods. + * @param <P> the type of the additional parameter used in the visitor's + * methods. + * @param visitor the visitor to apply to the element. + * @param param the additional parameter to be sent to the visitor. + * @return the return value from the visitor. + */ + <R,P> R accept(ElementVisitor<R,P> visitor, P param); + + /** + * <p>Returns {@code true} if this instance represents the same + * element as the one supplied.</p> + * <p>Please note that an element may not be equal to the same + * element provided by a different implementation of this framework, + * as the equivalence comparison may include the use of internal + * state which is inaccessible from the element's methods. This + * is similar to the way {@link Class} objects provided by different + * classloaders are not guaranteed to be equal.</p> + * + * @param obj the object to compare. + * @return {@code true} if {@code this} and {@code obj} represent + * the same element. + */ + boolean equals(Object obj); + + /** + * <p>Returns the element's annotation for the specified annotation type, + * if present, or {@code null} if not. The annotation may be directly + * present on the element or inherited.</p> + * <p>If the annotation contains an element of type {@code Class} or + * {@code Class[]}, attempts to read such an object will result in + * a {@link javax.lang.model.type.MirroredTypeException} or + * {@link javax.lang.model.type.MirroredTypesException} respectively. + * This is because information required to load the class (such as its + * class loader) is unavailable and so it may not be possible to load + * the class at all.</p> + * <p>Note that, unlike other methods in this framework, this method + * operates on runtime information obtained through reflection. + * As a result, the methods of the returned annotation object may + * throw exceptions relating to reflection failures.</p> + * + * @param <A> the type of annotation. + * @param annonType the {@code Class} object representing the annotation type. + * @return an annotation of the specified type, if present, or {@code null}. + * @see #getAnnotationMirrors() + * @see Elements#getAllAnnotationMirrors(Element) + * @see java.lang.reflect.AnnotatedElement#getAnnotation(Class) + * @see java.lang.annotation.AnnotationTypeMismatchException + * @see java.lang.annotation.IncompleteAnnotationException + * @see javax.lang.model.type.MirroredTypeException + * @see javax.lang.model.type.MirroredTypesException + */ + <A extends Annotation> A getAnnotation(Class<A> annonType); + + /** + * Returns the elements directly enclosed by this element. + * For example, a class element encloses constructor, method, + * field and further class elements. The returned list + * includes elements automatically generated by the compiler + * such as the default constructor and {@code values} and + * {@code valueOf} methods present in enumerations. Package + * elements contain class and interface elements, but not + * other packages. All other types of element do not contain + * other elements at this time. + * + * @return the enclosed elements, or an empty list if the + * element has none. + * @see Elements#getAllMembers(TypeElement) + */ + List<? extends Element> getEnclosedElements(); + + /** + * Returns the element that encloses this element. For a top-level + * type, its package is returned. Package and type parameter + * elements return {@code null}. + * + * @return the enclosing element or {@code null} if there isn't one. + * @see Elements#getPackageOf(Element) + */ + Element getEnclosingElement(); + + /** + * Returns the kind of this element. + * + * @return the kind of element. + */ + ElementKind getKind(); + + /** + * Obeys the general contract of {@link java.lang.Object#hashCode()}. + * + * @return a hash code for this element. + * @see #equals(Object) + */ + int hashCode(); + + /** + * Returns the type defined by this element. A generic + * element defines not one type, but a family of types. + * For such elements, a prototypical type is returned + * i.e. the element {@code Set<N extends Number>} will + * return the type {@code Set<N>}. The methods of + * {@link javax.lang.model.util.Types} should be used to + * obtain the full family of types. + * + * @return the type defined by this element. + * @see javax.lang.model.util.Types + */ + TypeMirror asType(); + + /** + * Returns the annotations directly present on this element. + * To obtain inherited annotations as well, call + * the {@link javax.lang.model.util.Elements#getAllAnnotationMirrors()} + * method of {@link javax.lang.model.util.Elements}. + * + * @return the annotations directly present on this element or + * an empty list if there are none. + * @see javax.lang.model.util.ElementFilter + */ + List<? extends AnnotationMirror> getAnnotationMirrors(); + + /** + * Returns the modifiers attached to this element, other than + * annotations e.g. {@code public} or {@code abstract}. If + * there are no modifiers, an empty set is returned. + * + * @return the modifiers of this element. + */ + Set<Modifier> getModifiers(); + + /** + * Returns the simple name of this element i.e. without any + * package prefix. The simple name of a generic type is the + * same as that of the raw variant i.e. {@code Set<E>}'s simple + * name is {@code "Set"}. Constructors are named {@code "<init>"} + * and static initializers {@code "<clinit>"}. Unnamed packages, + * anonymous classes and instance initializers all return the + * empty string, {@code ""}. + * + * @return the simple name of this element. + */ + Name getSimpleName(); + +} |