TypeVariable (Java SE 13 & JDK 13 )
- Type Parameters:
D- the type of generic declaration that declared the underlying type variable.
- All Superinterfaces:
AnnotatedElement,Type
public interface TypeVariable<D extends GenericDeclaration> extends Type, AnnotatedElement
TypeVariable is the common superinterface for type variables of kinds. A type variable is created the first time it is needed by a reflective method, as specified in this package. If a type variable t is referenced by a type (i.e, class, interface or annotation type) T, and T is declared by the nth enclosing class of T (see JLS 8.1.2), then the creation of t requires the resolution (see JVMS 5) of the ith enclosing class of T, for i = 0 to n, inclusive. Creating a type variable must not cause the creation of its bounds. Repeated creation of a type variable has no effect.
Multiple objects may be instantiated at run-time to represent a given type variable. Even though a type variable is created only once, this does not imply any requirement to cache instances representing the type variable. However, all instances representing a type variable must be equal() to each other. As a consequence, users of type variables must not rely on the identity of instances of classes implementing this interface.
- Since:
- 1.5
-
Method Summary
Modifier and Type Method Description AnnotatedType[]getAnnotatedBounds()Returns an array of AnnotatedType objects that represent the use of types to denote the upper bounds of the type parameter represented by this TypeVariable.
Type[]getBounds()Returns an array of
Typeobjects representing the upper bound(s) of this type variable.DgetGenericDeclaration()Returns the
GenericDeclarationobject representing the generic declaration declared for this type variable.StringgetName()Returns the name of this type variable, as it occurs in the source code.
-
Method Details
-
getBounds
Type[] getBounds()
Returns an array of
Typeobjects representing the upper bound(s) of this type variable. If no upper bound is explicitly declared, the upper bound isObject.For each upper bound B:
- if B is a parameterized
type or a type variable, it is created, (see
ParameterizedTypefor the details of the creation process for parameterized types). - Otherwise, B is resolved.
- Returns:
- an array of
Types representing the upper bound(s) of this type variable - Throws:
TypeNotPresentException- if any of the bounds refers to a non-existent type declarationMalformedParameterizedTypeException- if any of the bounds refer to a parameterized type that cannot be instantiated for any reason
- if B is a parameterized
type or a type variable, it is created, (see
-
getGenericDeclaration
D getGenericDeclaration()
Returns the
GenericDeclarationobject representing the generic declaration declared for this type variable.- Returns:
- the generic declaration declared for this type variable.
- Since:
- 1.5
-
getName
Returns the name of this type variable, as it occurs in the source code.
- Returns:
- the name of this type variable, as it appears in the source code
-
getAnnotatedBounds
Returns an array of AnnotatedType objects that represent the use of types to denote the upper bounds of the type parameter represented by this TypeVariable. The order of the objects in the array corresponds to the order of the bounds in the declaration of the type parameter. Note that if no upper bound is explicitly declared, the upper bound is unannotated
Object.- Returns:
- an array of objects representing the upper bound(s) of the type variable
- Since:
- 1.8
-
Report a bug or suggest an enhancement
For further API reference and developer documentation see the Java SE Documentation, which contains more detailed, developer-targeted descriptions with conceptual overviews, definitions of terms, workarounds, and working code examples.
Java is a trademark or registered trademark of Oracle and/or its affiliates in the US and other countries.
Copyright © 1993, 2019, Oracle and/or its affiliates, 500 Oracle Parkway, Redwood Shores, CA 94065 USA.
All rights reserved. Use is subject to license terms and the documentation redistribution policy.