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Interface Element
- All Superinterfaces:
-
AnnotatedConstruct
- All Known Subinterfaces:
ExecutableElement
,ModuleElement
,PackageElement
,Parameterizable
,QualifiedNameable
,RecordComponentElement
,TypeElement
,TypeParameterElement
,VariableElement
public interface Element extends AnnotatedConstruct
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.
- Since:
- 1.6
- See Also:
Method Summary
Modifier and Type | Method | Description |
---|---|---|
<R, |
accept |
Applies a visitor to this element.
|
TypeMirror |
asType() |
Returns the type defined by this element.
|
boolean |
equals |
Returns true if the argument represents the same element as this , or false otherwise.
|
<A extends Annotation> |
getAnnotation |
Returns this construct's annotation of the specified type if such an annotation is present, else null .
|
List<? extends AnnotationMirror> |
getAnnotationMirrors() |
Returns the annotations that are directly present on this construct.
|
<A extends Annotation> |
getAnnotationsByType |
Returns annotations that are associated with this construct.
|
List<? extends Element> |
getEnclosedElements() |
Returns the elements that are, loosely speaking, directly enclosed by this element.
|
Element |
getEnclosingElement() |
Returns the innermost element within which this element is, loosely speaking, enclosed.
|
ElementKind |
getKind() |
Returns the kind of this element.
|
Set<Modifier> |
getModifiers() |
Returns the modifiers of this element, excluding annotations.
|
Name |
getSimpleName() |
Returns the simple (unqualified) name of this element.
|
int |
hashCode() |
Obeys the general contract of Object.hashCode .
|
Method Details
asType
TypeMirror asType()
- Returns:
- the type defined by this element
- See Also:
getKind
ElementKind getKind()
kind
of this element.
- The kind of a package is
PACKAGE
. - The kind of a module is
MODULE
. - The kind of a type element is one of
ANNOTATION_TYPE
,CLASS
,ENUM
,INTERFACE
, orRECORD
. - The kind of a variable is one of
ENUM_CONSTANT
,EXCEPTION_PARAMETER
,FIELD
,LOCAL_VARIABLE
,PARAMETER
,RESOURCE_VARIABLE
, orBINDING_VARIABLE
. - The kind of an executable is one of
CONSTRUCTOR
,INSTANCE_INIT
,METHOD
, orSTATIC_INIT
. - The kind of a type parameter is
TYPE_PARAMETER
. - The kind of a record component is
RECORD_COMPONENT
.
- Returns:
-
the
kind
of this element
getModifiers
Set<Modifier> getModifiers()
public
and static
modifiers of interface members, are included.
- Returns:
- the modifiers of this element, or an empty set if there are none
getSimpleName
Name getSimpleName()
java.util.Set<E>
is "Set"
. If this element represents an unnamed package or unnamed module, 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.
- Returns:
- the simple (unqualified) name of this element
- See Also:
getEnclosingElement
Element getEnclosingElement()
- If this element is one whose declaration is lexically enclosed immediately within the declaration of another element, that other element is returned.
- If this is a top-level class or interface, its package is returned.
- If this is a package, its module is returned if such a module exists. Otherwise,
null
is returned. - If this is a type parameter, the generic element of the type parameter is returned.
- If this is a method or constructor parameter, the executable element which declares the parameter is returned.
- If this is a record component, the record class which declares the record component is returned.
- If this is a module,
null
is returned.
- Returns:
-
the enclosing element, or
null
if there is none - See Also:
getEnclosedElements
List<? extends Element> getEnclosedElements()
- API Note:
-
Elements of certain kinds can be isolated using methods in
ElementFilter
. - Returns:
- the enclosed elements, or an empty list if none
- See Java Language Specification:
- 8.8.9 Default Constructor
8.9 Enum Classes
- See Also:
equals
boolean equals(Object obj)
true
if the argument represents the same element as this
, or false
otherwise.
- Overrides:
equals
in classObject
- API Note:
-
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. - Parameters:
obj
- the object to be compared with this element- Returns:
true
if the argument represents the same element asthis
, orfalse
otherwise- See Also:
hashCode
int hashCode()
Object.hashCode
.
getAnnotationMirrors
List<? extends AnnotationMirror> getAnnotationMirrors()
To get inherited annotations as well, use getAllAnnotationMirrors
.
Note that any annotations returned by this method are declaration annotations.
- Specified by:
getAnnotationMirrors
in interfaceAnnotatedConstruct
- Returns:
- the annotations directly present on this construct; an empty list if there are none
- Since:
- 1.6
getAnnotation
<A extends Annotation> A getAnnotation(Class<A> annotationType)
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.
Note that any annotation returned by this method is a declaration annotation.
- Specified by:
getAnnotation
in interfaceAnnotatedConstruct
- Type Parameters:
A
- the annotation type- Parameters:
annotationType
- theClass
object corresponding to the annotation type- Returns:
-
this construct's annotation of the specified type if such an annotation is present, else
null
- Since:
- 1.6
- See Also:
getAnnotationsByType
<A extends Annotation> A[] getAnnotationsByType(Class<A> annotationType)
AnnotatedConstruct.getAnnotation(Class)
is that this method detects if its argument is a repeatable annotation type, and if so, attempts to find one or more annotations of that type by "looking through" a container annotation.
The annotations 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.
Note that any annotations returned by this method are declaration annotations.
- Specified by:
getAnnotationsByType
in interfaceAnnotatedConstruct
- Type Parameters:
A
- the annotation type- Parameters:
annotationType
- theClass
object corresponding to the annotation type- Returns:
- this construct's annotations for the specified annotation type if present on this construct, else an empty array
- Since:
- 8
- See Also:
accept
<R, P> R accept(ElementVisitor<R,P> v, P p)
- Type Parameters:
R
- the return type of the visitor's methodsP
- the type of the additional parameter to the visitor's methods- Parameters:
v
- the visitor operating on this elementp
- additional parameter to the visitor- Returns:
- a visitor-specified result
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