Interface ClassDesc
- All Superinterfaces:
ConstantDesc
,TypeDescriptor
,TypeDescriptor.OfField<ClassDesc>
Anominal descriptor for a
Class
constant.For common system types, including all the primitive types, there are predefinedClassDesc constants inConstantDescs
. (Thejava.lang.constant
APIs considervoid
to be a primitive type.) To create aClassDesc for a class or interface type, useof(java.lang.String)
orofDescriptor(String)
; to create aClassDesc for an array type, useofDescriptor(String)
, or first obtain aClassDesc for the component type and then call thearrayType()
orarrayType(int)
methods.
- Since:
- 12
- See Also:
Nested Class Summary
Nested classes/interfaces declared in interface java.lang.invoke.TypeDescriptor
TypeDescriptor.OfField<F extendsTypeDescriptor.OfField<F>>,TypeDescriptor.OfMethod<F extendsTypeDescriptor.OfField<F>,M extendsTypeDescriptor.OfMethod<F,
M>> Method Summary
Modifier and TypeMethodDescriptionarrayType
(int rank) defaultClassDesc
Returns the component type of thisClassDesc, if it describes an array type, ornull
otherwise.Returns a field type descriptor string for this typeReturns a human-readable name for thisClassDesc
.boolean
Compare the specified object with this descriptor for equality.default boolean
isArray()
Returns whether thisClassDesc describes an array type.default boolean
Returns whether thisClassDesc describes a class or interface type.default boolean
Returns whether thisClassDesc describes a primitive type.defaultClassDesc
defaultClassDesc
staticClassDesc
Returns aClassDesc for a class or interface type, given the name of the class or interface, such as"java.lang.String"
.staticClassDesc
Returns aClassDesc for a class or interface type, given a package name and the unqualified (simple) name for the class or interface.staticClassDesc
ofDescriptor
(String descriptor) Returns aClassDesc given a descriptor string for a class, interface, array, or primitive type.staticClassDesc
ofInternalName
(String name) Returns aClassDesc for a class or interface type, given the name of the class or interface in internal form, such as"java/lang/String"
.defaultString
Returns the package name of thisClassDesc, if it describes a class or interface type.Class
<?>
Method Details
of
Returns aClassDesc for a class or interface type, given the name of the class or interface, such as"java.lang.String"
. (To create a descriptor for an array type, either useofDescriptor(String)
orarrayType()
; to create a descriptor for a primitive type, useofDescriptor(String)
or use the predefined constants inConstantDescs
).- Parameters:
name
- the fully qualified (dot-separated) binary class name- Returns:
- aClassDesc describing the desired class
- Throws:
NullPointerException
- if the argument isnull
IllegalArgumentException
- if the name string is not in the correct format- See Also:
ofInternalName
Returns aClassDesc for a class or interface type, given the name of the class or interface in internal form, such as"java/lang/String"
.- API Note:
- To create a descriptor for an array type, either use
ofDescriptor(String)
orarrayType()
; to create a descriptor for a primitive type, useofDescriptor(String)
or use the predefined constants inConstantDescs
. - Parameters:
name
- the fully qualified class name, in internal (slash-separated) form- Returns:
- aClassDesc describing the desired class
- Throws:
NullPointerException
- if the argument isnull
IllegalArgumentException
- if the name string is not in the correct format- SeeJava Virtual Machine Specification:
- 4.2.1 Binary Class and Interface Names
- Since:
- 20
- See Also:
of
Returns aClassDesc for a class or interface type, given a package name and the unqualified (simple) name for the class or interface.- Parameters:
packageName
- the package name (dot-separated); if the package name is the empty string, the class is considered to be in the unnamed packageclassName
- the unqualified (simple) class name- Returns:
- aClassDesc describing the desired class
- Throws:
NullPointerException
- if any argument isnull
IllegalArgumentException
- if the package name or class name are not in the correct format
ofDescriptor
Returns aClassDesc given a descriptor string for a class, interface, array, or primitive type.- API Note:
- A field type descriptor string for a non-array type is either a one-letter code corresponding to a primitive type (
"J", "I", "C", "S", "B", "D", "F", "Z", "V"
), or the letter"L"
, followed by the fully qualified binary name of a class, followed by";"
. A field type descriptor for an array type is the character"["
followed by the field descriptor for the component type. Examples of valid type descriptor strings include"Ljava/lang/String;"
,"I"
,"[I"
,"V"
,"[Ljava/lang/String;"
, etc. See JVMS4.3.2("Field Descriptors") for more detail. - Parameters:
descriptor
- a field descriptor string- Returns:
- aClassDesc describing the desired class
- Throws:
NullPointerException
- if the argument isnull
IllegalArgumentException
- if the descriptor string is not in the correct format- SeeJava Virtual Machine Specification:
- 4.3.2 Field Descriptors
4.4.1 The CONSTANT_Class_info Structure - See Also:
arrayType
ClassDesc arrayType()- Specified by:
arrayType
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- aClassDesc describing the array type
- Throws:
IllegalStateException
- if the resultingClassDesc would have an array rank of greater than 255- SeeJava Virtual Machine Specification:
- 4.4.1 The CONSTANT_Class_info Structure
arrayType
Returns aClassDesc for an array type of the specified rank, whose component type is described by thisClassDesc.- Parameters:
rank
- the rank of the array- Returns:
- aClassDesc describing the array type
- Throws:
IllegalArgumentException
- if the rank is less than or equal to zero or if the rank of the resulting array type is greater than 255- SeeJava Virtual Machine Specification:
- 4.4.1 The CONSTANT_Class_info Structure
nested
- API Note:
- Example: If descriptor
d
describes the classjava.util.Map
, a descriptor for the classjava.util.Map.Entry
could be obtained byd.nested("Entry")
. - Parameters:
nestedName
- the unqualified name of the nested class- Returns:
- aClassDesc describing the nested class
- Throws:
NullPointerException
- if the argument isnull
IllegalStateException
- if thisClassDesc does not describe a class or interface typeIllegalArgumentException
- if the nested class name is invalid
nested
- Parameters:
firstNestedName
- the unqualified name of the first level of nested classmoreNestedNames
- the unqualified name(s) of the remaining levels of nested class- Returns:
- aClassDesc describing the nested class
- Throws:
NullPointerException
- if any argument or its contents isnull
IllegalStateException
- if thisClassDesc does not describe a class or interface typeIllegalArgumentException
- if the nested class name is invalid
isArray
default boolean isArray()Returns whether thisClassDesc describes an array type.- Specified by:
isArray
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- whether thisClassDesc describes an array type
isPrimitive
default boolean isPrimitive()Returns whether thisClassDesc describes a primitive type.- Specified by:
isPrimitive
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- whether thisClassDesc describes a primitive type
isClassOrInterface
componentType
Returns the component type of thisClassDesc, if it describes an array type, ornull
otherwise.- Specified by:
componentType
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- aClassDesc describing the component type, or
null
if this descriptor does not describe an array type
packageName
displayName
String displayName()Returns a human-readable name for thisClassDesc
. For primitive types, this method returns the simple name (such asint
). For class or interface types, this method returns the unqualified class name. For array types, this method returns the human-readable name of the component type suffixed with the appropriate number of[]
pairs.- Returns:
- a human-readable name for this
ClassDesc
descriptorString
String descriptorString()Returns a field type descriptor string for this type- Specified by:
descriptorString
in interfaceTypeDescriptor
- Returns:
- the descriptor string
- SeeJava Virtual Machine Specification:
- 4.3.2 Field Descriptors
resolveConstantDesc
Description copied from interface:ConstantDesc
Resolves this descriptor reflectively, emulating the resolution behavior of JVMS5.4.3 and the access control behavior of JVMS5.4.4. The resolution and access control context is provided by theMethodHandles.Lookup
parameter. No caching of the resulting value is performed.- Specified by:
resolveConstantDesc
in interfaceConstantDesc
- Parameters:
lookup
- TheMethodHandles.Lookup
to provide name resolution and access control context- Returns:
- the resolved constant value
- Throws:
ReflectiveOperationException
- if a class, method, or field could not be reflectively resolved in the course of resolution- Since:
- 21
equals