Interface ClassDesc
- All Superinterfaces:
ConstantDesc
,TypeDescriptor
,TypeDescriptor.OfField<ClassDesc>
A nominal descriptor for a
Class
constant.
For common system types, including all the primitive types, there are
predefined ClassDesc constants in ConstantDescs
.
(The java.lang.constant
APIs consider void
to be a primitive type.)
To create a ClassDesc for a class or interface type, use of(java.lang.String)
or
ofDescriptor(String)
; to create a ClassDesc for an array
type, use ofDescriptor(String)
, or first obtain a
ClassDesc for the component type and then call the arrayType()
or arrayType(int)
methods.
- Since:
- 12
- See Also:
-
Nested Class Summary
Nested classes/interfaces declared in interface java.lang.invoke.TypeDescriptor
TypeDescriptor.OfField<F extends TypeDescriptor.OfField<F>>, TypeDescriptor.OfMethod<F extends TypeDescriptor.OfField<F>, M extends TypeDescriptor.OfMethod<F,
M>> -
Method Summary
Modifier and TypeMethodDescriptionarrayType
(int rank) default ClassDesc
Returns the component type of this ClassDesc, 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 this ClassDesc describes an array type.default boolean
Returns whether this ClassDesc describes a class or interface type.default boolean
Returns whether this ClassDesc describes a primitive type.default ClassDesc
default ClassDesc
static ClassDesc
Returns a ClassDesc for a class or interface type, given the name of the class or interface, such as"java.lang.String"
.static ClassDesc
Returns a ClassDesc for a class or interface type, given a package name and the unqualified (simple) name for the class or interface.static ClassDesc
ofDescriptor
(String descriptor) Returns a ClassDesc given a descriptor string for a class, interface, array, or primitive type.static ClassDesc
ofInternalName
(String name) Returns a ClassDesc for a class or interface type, given the name of the class or interface in internal form, such as"java/lang/String"
.default String
Returns the package name of this ClassDesc, if it describes a class or interface type.Class
<?>
-
Method Details
-
of
Returns a ClassDesc 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:
- a ClassDesc 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 a ClassDesc 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:
- a ClassDesc describing the desired class
- Throws:
NullPointerException
- if the argument isnull
IllegalArgumentException
- if the name string is not in the correct format- See Java Virtual Machine Specification:
-
4.2.1 Binary Class and Interface Names
- Since:
- 20
- See Also:
-
of
Returns a ClassDesc 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:
- a ClassDesc 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 a ClassDesc 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 JVMS 4.3.2 ("Field Descriptors") for more detail. - Parameters:
descriptor
- a field descriptor string- Returns:
- a ClassDesc describing the desired class
- Throws:
NullPointerException
- if the argument isnull
IllegalArgumentException
- if the descriptor string is not in the correct format- See Java 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:
- a ClassDesc describing the array type
- Throws:
IllegalStateException
- if the resulting ClassDesc would have an array rank of greater than 255- See Java Virtual Machine Specification:
-
4.4.1 The CONSTANT_Class_info Structure
-
arrayType
Returns a ClassDesc for an array type of the specified rank, whose component type is described by this ClassDesc.- Parameters:
rank
- the rank of the array- Returns:
- a ClassDesc 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- See Java 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:
- a ClassDesc describing the nested class
- Throws:
NullPointerException
- if the argument isnull
IllegalStateException
- if this ClassDesc 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:
- a ClassDesc describing the nested class
- Throws:
NullPointerException
- if any argument or its contents isnull
IllegalStateException
- if this ClassDesc does not describe a class or interface typeIllegalArgumentException
- if the nested class name is invalid
-
isArray
default boolean isArray()Returns whether this ClassDesc describes an array type.- Specified by:
isArray
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- whether this ClassDesc describes an array type
-
isPrimitive
default boolean isPrimitive()Returns whether this ClassDesc describes a primitive type.- Specified by:
isPrimitive
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- whether this ClassDesc describes a primitive type
-
isClassOrInterface
-
componentType
Returns the component type of this ClassDesc, if it describes an array type, ornull
otherwise.- Specified by:
componentType
in interfaceTypeDescriptor.OfField<ClassDesc>
- Returns:
- a ClassDesc 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
- See Java Virtual Machine Specification:
-
4.3.2 Field Descriptors
-
resolveConstantDesc
Description copied from interface:ConstantDesc
Resolves this descriptor reflectively, emulating the resolution behavior of JVMS 5.4.3 and the access control behavior of JVMS 5.4.4. 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
Compare the specified object with this descriptor for equality. Returnstrue
if and only if the specified object is also a ClassDesc and both describe the same type.
-