net.jqwik.api.providers

Interface TypeUsage

@API(status=MAINTAINED,
     since="1.0")
public interface TypeUsage

An instance of TypeUsage describes the information available for parameter or return types. The class is supposed to relieve its users from all the intricacies of the Java reflection API. Doing that it will resolve meta annotations, repeated annotations as well as annotated type parameters.

TypeUsage provides access to:

• the native type of an object
• the component type (if it's an array)
• the type parameters (again as instances of TypeUsage)
• the annotations (if the object is derived from a parameter)
• methods to test for compatibility of types that do also handle compatibility between raw types and boxed type

Within the public API TypeUsage is used in two places:

• @see ArbitraryProvider
• @see Arbitraries.defaultFor(Class, Class[])

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	TypeUsage.Enhancer Enhancers can manipulate the perceived type of parameters.
static class	TypeUsage.TypeUsageFacade

Field Summary

Fields

Modifier and Type	Field and Description
static TypeUsage	OBJECT_TYPE

Method Summary

Modifier and Type	Method and Description
TypeUsage	asNotNullable() Return type usage object with just nullablity set to false
TypeUsage	asNullable() Return type usage object with just nullablity set to true
boolean	canBeAssignedTo(TypeUsage targetType) Check if an instance can be assigned to another TypeUsage instance.
<A extends java.lang.annotation.Annotation> java.util.Optional<A>	findAnnotation(java.lang.Class<A> annotationType) Return an Optional of the first instance of a specific annotationType if there is one (directly or indirectly through meta-annotations).
static TypeUsage	forType(java.lang.reflect.Type type)
java.lang.reflect.AnnotatedType	getAnnotatedType()
java.util.List<java.lang.annotation.Annotation>	getAnnotations() Return all annotations of a parameter (or an annotated type argument).
java.util.Optional<TypeUsage>	getComponentType() Return an Optional of an array's component type - if it is an array.
java.util.List<TypeUsage>	getInterfaces() Return interfaces of this type.
java.util.List<TypeUsage>	getLowerBounds() Return lower bounds if a generic type is a wildcard.
java.util.Optional<java.lang.Object>	getMetaInfo(java.lang.String key) Get meta info for a certain key
java.lang.Class<?>	getRawType() Return the raw type which is usually the class or interface you see in a parameters or return values specification.
java.util.Optional<TypeUsage>	getSuperclass() Return superclass of this type.
java.util.List<TypeUsage>	getSuperTypes() List of superclass and interfaces.
java.lang.reflect.Type	getType()
TypeUsage	getTypeArgument(int position) Return the type argument at a specific position.
java.util.List<TypeUsage>	getTypeArguments() Return the type arguments of a generic type in the order of there appearance in a type's declaration.
java.lang.String	getTypeVariable()
java.util.List<TypeUsage>	getUpperBounds() Return upper bounds if a generic type is a wildcard or type variable.
<A extends java.lang.annotation.Annotation> boolean	isAnnotated(java.lang.Class<A> annotationType) Return true if the current instance is annotated (directly or indirectly through meta-annotations) with a specific annotationType.
boolean	isArray() Return true if a type is an array type.
boolean	isAssignableFrom(java.lang.Class<?> providedClass) Check if a given providedClass is assignable from this generic type.
boolean	isEnum() Return true if a type is an enum type.
boolean	isExtendsConstraint() Return true if it is a wildcard with extends constraint, e.g.
boolean	isGeneric() Return true if a type has any type arguments itself.
boolean	isNullable() Return optional true if this type is nullable.
boolean	isOfType(java.lang.Class<?> aRawType) Check if an instance is of a specific raw type Most of the time this is what you want to do when checking for applicability of a ArbitraryProvider.
boolean	isParameterizedRaw() Return true if it is a parameterized type with no parameters, e.g.
boolean	isSuperWildcard() Return true if it is a wildcard with super constraint, e.g.
boolean	isTypeVariable() Return true if a generic type is a wildcard.
boolean	isTypeVariableOrWildcard() Return true if a generic type is a type variable or a wildcard.
boolean	isVoid() Return true if type is Void.
boolean	isWildcard() Return true if a generic type is a wildcard.
static TypeUsage	of(java.lang.Class<?> type, TypeUsage... typeParameters)
static TypeUsage	wildcard(TypeUsage upperBound)
<A extends java.lang.annotation.Annotation> TypeUsage	withAnnotation(A annotation) Return type usage object with additional annotation
TypeUsage	withMetaInfo(java.lang.String key, java.lang.Object value) Return type usage object with additional meta info

Field Detail

OBJECT_TYPE

@API(status=INTERNAL)
static final TypeUsage OBJECT_TYPE

Method Detail

of

static TypeUsage of(java.lang.Class<?> type,
                    TypeUsage... typeParameters)

wildcard

static TypeUsage wildcard(TypeUsage upperBound)

forType

static TypeUsage forType(java.lang.reflect.Type type)

getRawType

java.lang.Class<?> getRawType()

Return the raw type which is usually the class or interface you see in a parameters or return values specification.

A raw type always exists.

getUpperBounds

java.util.List<TypeUsage> getUpperBounds()

Return upper bounds if a generic type is a wildcard or type variable. TypeUsage.of(Object.class) is always included.

getLowerBounds

java.util.List<TypeUsage> getLowerBounds()

Return lower bounds if a generic type is a wildcard.

isWildcard

boolean isWildcard()

Return true if a generic type is a wildcard.

isTypeVariable

boolean isTypeVariable()

Return true if a generic type is a wildcard.

isTypeVariableOrWildcard

boolean isTypeVariableOrWildcard()

Return true if a generic type is a type variable or a wildcard.

getTypeArguments

java.util.List<TypeUsage> getTypeArguments()

Return the type arguments of a generic type in the order of there appearance in a type's declaration.

getTypeArgument

TypeUsage getTypeArgument(int position)

Return the type argument at a specific position.

isOfType

boolean isOfType(java.lang.Class<?> aRawType)

Check if an instance is of a specific raw type

Most of the time this is what you want to do when checking for applicability of a ArbitraryProvider.

canBeAssignedTo

boolean canBeAssignedTo(TypeUsage targetType)

Check if an instance can be assigned to another TypeUsage instance.

isGeneric

boolean isGeneric()

Return true if a type has any type arguments itself.

isEnum

boolean isEnum()

Return true if a type is an enum type.

isArray

boolean isArray()

Return true if a type is an array type.

getAnnotations

java.util.List<java.lang.annotation.Annotation> getAnnotations()

Return all annotations of a parameter (or an annotated type argument).

This list already contains all meta annotations, repeated annotations and annotations from annotated type arguments. Thus, it does much more than the usual Java reflection API.

findAnnotation

<A extends java.lang.annotation.Annotation> java.util.Optional<A> findAnnotation(java.lang.Class<A> annotationType)

Return an Optional of the first instance of a specific annotationType if there is one (directly or indirectly through meta-annotations).

isAnnotated

<A extends java.lang.annotation.Annotation> boolean isAnnotated(java.lang.Class<A> annotationType)

Return true if the current instance is annotated (directly or indirectly through meta-annotations) with a specific annotationType.

isAssignableFrom

boolean isAssignableFrom(java.lang.Class<?> providedClass)

Check if a given providedClass is assignable from this generic type.

getComponentType

java.util.Optional<TypeUsage> getComponentType()

Return an Optional of an array's component type - if it is an array.

isVoid

@API(status=EXPERIMENTAL,
     since="1.2.0")
boolean isVoid()

Return true if type is Void.

getSuperclass

@API(status=EXPERIMENTAL,
     since="1.2.0")
java.util.Optional<TypeUsage> getSuperclass()

Return superclass of this type. With all type variables resolved.

getSuperTypes

@API(status=EXPERIMENTAL,
     since="1.8.0")
java.util.List<TypeUsage> getSuperTypes()

List of superclass and interfaces. With all type variables resolved.

getInterfaces

@API(status=EXPERIMENTAL,
     since="1.2.0")
java.util.List<TypeUsage> getInterfaces()

Return interfaces of this type. With all type variables resolved.

getType

@API(status=INTERNAL,
     since="1.2.0")
java.lang.reflect.Type getType()

getAnnotatedType

@API(status=INTERNAL,
     since="1.2.0")
java.lang.reflect.AnnotatedType getAnnotatedType()

isNullable

@API(status=EXPERIMENTAL,
     since="1.6.0")
boolean isNullable()

Return optional true if this type is nullable.

Plain Java types are never nullable. Nullability must be set explicitly using asNullable(). This is usually done in registered enhancers.

isParameterizedRaw

@API(status=EXPERIMENTAL,
     since="1.8.0")
boolean isParameterizedRaw()

Return true if it is a parameterized type with no parameters, e.g. List.

isSuperWildcard

@API(status=EXPERIMENTAL,
     since="1.8.0")
boolean isSuperWildcard()

Return true if it is a wildcard with super constraint, e.g. ? super String.

isExtendsConstraint

@API(status=EXPERIMENTAL,
     since="1.8.0")
boolean isExtendsConstraint()

Return true if it is a wildcard with extends constraint, e.g. ? extends String.

asNullable

@API(status=EXPERIMENTAL,
     since="1.6.0")
TypeUsage asNullable()

Return type usage object with just nullablity set to true

asNotNullable

@API(status=EXPERIMENTAL,
     since="1.6.0")
TypeUsage asNotNullable()

Return type usage object with just nullablity set to false

getTypeVariable

@API(status=EXPERIMENTAL,
     since="1.6.0")
java.lang.String getTypeVariable()

withAnnotation

@API(status=EXPERIMENTAL,
     since="1.6.0")
<A extends java.lang.annotation.Annotation> TypeUsage withAnnotation(A annotation)

Return type usage object with additional annotation

getMetaInfo

@API(status=EXPERIMENTAL,
     since="1.6.0")
java.util.Optional<java.lang.Object> getMetaInfo(java.lang.String key)

Get meta info for a certain key

withMetaInfo

@API(status=EXPERIMENTAL,
     since="1.6.0")
TypeUsage withMetaInfo(java.lang.String key,
                                                                     java.lang.Object value)

Return type usage object with additional meta info