Module java.compiler

Package javax.lang.model.type

Interface TypeMirror

All Superinterfaces:

AnnotatedConstruct

All Known Subinterfaces:

ArrayType, DeclaredType, ErrorType, ExecutableType, IntersectionType, NoType, NullType, PrimitiveType, ReferenceType, TypeVariable, UnionType, WildcardType

public interface TypeMirror
extends AnnotatedConstruct

Represents a type in the Java programming language. Types include primitive types, declared types (class and interface types), array types, type variables, and the null type. Also represented are wildcard type arguments, the signature and return types of executables, and pseudo-types corresponding to packages, modules, and the keyword void.

Types should be compared using the utility methods in Types. There is no guarantee that any particular type will always be represented by the same object.

To implement operations based on the class of an TypeMirror 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 TypeMirror subinterfaces.

See Java Language Specification:

4.1 The Kinds of Types and Values
4.2 Primitive Types and Values
4.3 Reference Types and Values
4.4 Type Variables
4.5 Parameterized Types
4.8 Raw Types
4.9 Intersection Types
10.1 Array Types

Since:

1.6

See Also:

• Element
• Types

Method Summary

Modifier and Type	Method	Description
<R, P> R	accept(TypeVisitor<R,P> v, P p)	Applies a visitor to this type.
boolean	equals(Object obj)	Obeys the general contract of Object.equals.
<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.
List<? extends AnnotationMirror>	getAnnotationMirrors()	Returns the annotations that are directly present on this construct.
<A extends Annotation> A[]	getAnnotationsByType(Class<A> annotationType)	Returns annotations that are associated with this construct.
TypeKind	getKind()	Returns the kind of this type.
int	hashCode()	Obeys the general contract of Object.hashCode.
String	toString()	Returns an informative string representation of this type.

Method Details

getKind

TypeKind getKind()

Returns the kind of this type.

• The kind of a primitive type is one of the kinds for which TypeKind.isPrimitive() returns true.
• The kind of a null type is NULL.
• The kind of an array type is ARRAY.
• The kind of a declared type is DECLARED.
• The kind of an error type is ERROR.
• The kind of a type variable is TYPEVAR.
• The kind of a wildcard type is WILDCARD.
• The kind of an executable type is EXECUTABLE.
• The kind of a pseudo-type is one of VOID, PACKAGE, MODULE, or NONE.
• The kind of a union type is UNION.
• The kind of an intersection type is INTERSECTION.

Returns:

the kind of this type

equals

boolean equals(Object obj)

Obeys the general contract of Object.equals. This method does not, however, indicate whether two types represent the same type. Semantic comparisons of type equality should instead use Types.isSameType(TypeMirror, TypeMirror). The results of t1.equals(t2) and Types.isSameType(t1, t2) may differ.

Overrides:

equals in class Object

Parameters:

obj - the object to be compared with this type

Returns:

true if the specified object is equal to this one

See Also:

• Object.hashCode()
• HashMap

hashCode

int hashCode()

Obeys the general contract of Object.hashCode.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object

See Also:

• equals(java.lang.Object)

toString

String toString()

Returns an informative string representation of this type. If possible, the string should be of a form suitable for representing this type in source code. Any names embedded in the result are qualified if possible.

Overrides:

toString in class Object

Returns:

a string representation of this type

getAnnotationMirrors

List<? extends AnnotationMirror> getAnnotationMirrors()

Returns the annotations that are directly present on this construct.

Note that any annotations returned by this method are type annotations.

Specified by:

getAnnotationMirrors in interface AnnotatedConstruct

Returns:

the annotations directly present on this construct; an empty list if there are none

Since:

1.8

getAnnotation

<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 interfaces 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 interfaces.

Note that any annotation returned by this method is a type annotation.

Specified by:

getAnnotation in interface AnnotatedConstruct

Type Parameters:

A - the annotation interface

Parameters:

annotationType - the Class object corresponding to the annotation interface

Returns:

this construct's annotation of the specified type if such an annotation is present, else null

Since:

1.8

See Also:

• AnnotatedConstruct.getAnnotationMirrors()
• AnnotatedElement.getAnnotation(java.lang.Class<T>)
• EnumConstantNotPresentException
• AnnotationTypeMismatchException
• IncompleteAnnotationException
• MirroredTypeException
• MirroredTypesException

getAnnotationsByType

<A extends Annotation> A[] getAnnotationsByType(Class<A> annotationType)

Returns annotations that are associated with this construct. If there are no annotations associated with this construct, the return value is an array of length 0. The order of annotations which are directly or indirectly present on a construct C is computed as if indirectly present annotations on C are directly present on C in place of their container annotation, in the order in which they appear in the value element of the container annotation. The difference between this method and AnnotatedConstruct.getAnnotation(Class) is that this method detects if its argument is a repeatable annotation interface, 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 interfaces 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 interfaces.

Note that any annotations returned by this method are type annotations.

Specified by:

getAnnotationsByType in interface AnnotatedConstruct

Type Parameters:

A - the annotation interface

Parameters:

annotationType - the Class object corresponding to the annotation interface

Returns:

this construct's annotations for the specified annotation type if present on this construct, else an empty array

Since:

1.8

See Also:

• AnnotatedConstruct.getAnnotationMirrors()
• AnnotatedConstruct.getAnnotation(Class)
• AnnotatedElement.getAnnotationsByType(Class)
• EnumConstantNotPresentException
• AnnotationTypeMismatchException
• IncompleteAnnotationException
• MirroredTypeException
• MirroredTypesException

accept

<R,
P> R accept(TypeVisitor<R,P> v,
 P p)

Applies a visitor to this type.

Type Parameters:

R - the return type of the visitor's methods

P - the type of the additional parameter to the visitor's methods

Parameters:

v - the visitor operating on this type

p - additional parameter to the visitor

Returns:

a visitor-specified result