public interface Element extends AnnotatedConstruct
Represents a program element such as a package, class, or method. Each element represents a static, language-level construct (and not, for example, a runtime construct of the virtual machine).
Elements should be compared using the equals(Object)
method. There is no guarantee that any particular element will always be represented by the same object.
To implement operations based on the class of an Element
object, either use a visitor or use the result of the getKind()
method. Using instanceof
is not necessarily a reliable idiom for determining the effective class of an object in this modeling hierarchy since an implementation may choose to have a single object implement multiple Element
subinterfaces.
Elements
, TypeMirror
TypeMirror asType()
Returns the type defined by this element.
A generic element defines a family of types, not just one. If this is a generic element, a prototypical type is returned. This is the element's invocation on the type variables corresponding to its own formal type parameters. For example, for the generic class element C<N extends Number>
, the parameterized type C<N>
is returned. The Types
utility interface has more general methods for obtaining the full range of types defined by an element.
Types
ElementKind getKind()
Returns the kind
of this element.
Set<Modifier> getModifiers()
Returns the modifiers of this element, excluding annotations. Implicit modifiers, such as the public
and static
modifiers of interface members, are included.
Name getSimpleName()
Returns the simple (unqualified) name of this element. The name of a generic type does not include any reference to its formal type parameters. For example, the simple name of the type element java.util.Set<E>
is "Set"
. If this element represents an unnamed package, an empty name is returned. If it represents a constructor, the name "<init>
" is returned. If it represents a static initializer, the name "<clinit>
" is returned. If it represents an anonymous class or instance initializer, an empty name is returned.
PackageElement.getSimpleName()
, ExecutableElement.getSimpleName()
, TypeElement.getSimpleName()
, VariableElement.getSimpleName()
Element getEnclosingElement()
Returns the innermost element within which this element is, loosely speaking, enclosed.
null
is returned. null
if there is noneElements.getPackageOf(javax.lang.model.element.Element)
List<? extends Element> getEnclosedElements()
Returns the elements that are, loosely speaking, directly enclosed by this element. A class or interface is considered to enclose the fields, methods, constructors, and member types that it directly declares. A package encloses the top-level classes and interfaces within it, but is not considered to enclose subpackages. Other kinds of elements are not currently considered to enclose any elements; however, that may change as this API or the programming language evolves.
Note that elements of certain kinds can be isolated using methods in ElementFilter
.
PackageElement.getEnclosedElements()
, TypeElement.getEnclosedElements()
, Elements.getAllMembers(javax.lang.model.element.TypeElement)
boolean equals(Object obj)
Returns true
if the argument represents the same element as this
, or false
otherwise.
Note that the identity of an element involves implicit state not directly accessible from the element's methods, including state about the presence of unrelated types. Element objects created by different implementations of these interfaces should not be expected to be equal even if "the same" element is being modeled; this is analogous to the inequality of Class
objects for the same class file loaded through different class loaders.
equals
in class Object
obj
- the object to be compared with this elementtrue
if the specified object represents the same element as thisObject.hashCode()
, HashMap
int hashCode()
Obeys the general contract of Object.hashCode
.
hashCode
in class Object
equals(java.lang.Object)
List<? extends AnnotationMirror> getAnnotationMirrors()
Returns the annotations that are directly present on this construct.
To get inherited annotations as well, use getAllAnnotationMirrors
.
getAnnotationMirrors
in interface AnnotatedConstruct
<A extends Annotation> A getAnnotation(Class<A> annotationType)
Returns this construct's annotation of the specified type if such an annotation is present, else null
.
The annotation returned by this method could contain an element whose value is of type Class
. This value cannot be returned directly: information necessary to locate and load a class (such as the class loader to use) is not available, and the class might not be loadable at all. Attempting to read a Class
object by invoking the relevant method on the returned annotation will result in a MirroredTypeException
, from which the corresponding TypeMirror
may be extracted. Similarly, attempting to read a Class[]
-valued element will result in a MirroredTypesException
.
Note: This method is unlike others in this and related interfaces. It operates on runtime reflective information — representations of annotation types currently loaded into the VM — rather than on the representations defined by and used throughout these interfaces. Consequently, calling methods on the returned annotation object can throw many of the exceptions that can be thrown when calling methods on an annotation object returned by core reflection. This method is intended for callers that are written to operate on a known, fixed set of annotation types.
getAnnotation
in interface AnnotatedConstruct
A
- the annotation typeannotationType
- the Class
object corresponding to the annotation typenull
AnnotatedConstruct.getAnnotationMirrors()
, AnnotatedElement.getAnnotation(java.lang.Class<T>)
, EnumConstantNotPresentException
, AnnotationTypeMismatchException
, IncompleteAnnotationException
, MirroredTypeException
, MirroredTypesException
<R,P> R accept(ElementVisitor<R,P> v, P p)
Applies a visitor to this element.
R
- the return type of the visitor's methodsP
- the type of the additional parameter to the visitor's methodsv
- the visitor operating on this elementp
- additional parameter to the visitor
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