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.

Since:
1.6
See Also:
Element, Types
  • Method Details

    • getKind

      TypeKind getKind()
      Returns the kind of this type.
      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:
      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 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 type annotation.

      Specified by:
      getAnnotation in interface AnnotatedConstruct
      Type Parameters:
      A - the annotation type
      Parameters:
      annotationType - the Class object corresponding to the annotation type
      Returns:
      this construct's annotation for the specified annotation type if present, else null
      Since:
      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 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 type annotations.

      Specified by:
      getAnnotationsByType in interface AnnotatedConstruct
      Type Parameters:
      A - the annotation type
      Parameters:
      annotationType - the Class 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:
      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