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T - the type of the class modeled by this Class
object. For example, the type of String.class is
Class<String>. Use Class<?> if the class being modeled is
unknown.Serializable, Constable, TypeDescriptor, TypeDescriptor.OfField<Class<?>>, AnnotatedElement, GenericDeclaration, Typepublic final class Class<T> extends Object implements Serializable, GenericDeclaration, Type, AnnotatedElement, TypeDescriptor.OfField<Class<?>>, Constable
Class represent classes and
interfaces in a running Java application. An enum type and a record
type are kinds of class; an annotation type is a kind of
interface. Every array also belongs to a class that is reflected as
a Class object that is shared by all arrays with the same
element type and number of dimensions. The primitive Java types
(boolean, byte, char, short,
int, long, float, and double), and the
keyword void are also represented as Class objects.
Class has no public constructor. Instead a Class
object is constructed automatically by the Java Virtual Machine when
a class is derived from the bytes of a class file through
the invocation of one of the following methods:
ClassLoader::defineClass
java.lang.invoke.MethodHandles.Lookup::defineClass
java.lang.invoke.MethodHandles.Lookup::defineHiddenClass
The methods of class Class expose many characteristics of a
class or interface. Most characteristics are derived from the class
file that the class loader passed to the Java Virtual Machine or
from the class file passed to Lookup::defineClass
or Lookup::defineHiddenClass.
A few characteristics are determined by the class loading environment
at run time, such as the module returned by getModule().
The following example uses a Class object to print the
class name of an object:
void printClassName(Object obj) {
System.out.println("The class of " + obj +
" is " + obj.getClass().getName());
}
It is also possible to get the Class object for a named
type (or for void) using a class literal.
For example:
System.out.println("The name of class Foo is: "+Foo.class.getName());
Some methods of class Class expose whether the declaration of
a class or interface in Java source code was enclosed within
another declaration. Other methods describe how a class or interface
is situated in a nest. A nest is a set of
classes and interfaces, in the same run-time package, that
allow mutual access to their private members.
The classes and interfaces are known as nestmates.
One nestmate acts as the
nest host, and enumerates the other nestmates which
belong to the nest; each of them in turn records it as the nest host.
The classes and interfaces which belong to a nest, including its host, are
determined when
class files are generated, for example, a Java compiler
will typically record a top-level class as the host of a nest where the
other members are the classes and interfaces whose declarations are
enclosed within the top-level class declaration.
A class or interface created by the invocation of
Lookup::defineHiddenClass is a hidden
class or interface.
All kinds of class, including enum types and record types, may be
hidden classes; all kinds of interface, including annotation types,
may be hidden interfaces.
The name of a hidden class or interface is
not a binary name,
which means the following:
Class::describeConstable,
ClassDesc::of, or
ClassDesc::ofDescriptor.
Class::forName
or ClassLoader::loadClass.
Class.ClassLoader.defineClass(byte[], int, int),
Serialized FormTypeDescriptor.OfField<F extends TypeDescriptor.OfField<F>>, TypeDescriptor.OfMethod<F extends TypeDescriptor.OfField<F>,M extends TypeDescriptor.OfMethod<F,M>>| Modifier and Type | Method | Description |
|---|---|---|
Class<?> |
arrayType() |
Returns a
Class for an array type whose component type
is described by this Class. |
<U> Class<? extends U> |
asSubclass(Class<U> clazz) |
Casts this
Class object to represent a subclass of the class
represented by the specified class object. |
T |
cast(Object obj) |
Casts an object to the class or interface represented
by this
Class object. |
Class<?> |
componentType() |
Returns the component type of this
Class, if it describes
an array type, or null otherwise. |
Optional<ClassDesc> |
describeConstable() |
Returns a nominal descriptor for this instance, if one can be
constructed, or an empty
Optional if one cannot be. |
String |
descriptorString() |
Returns the descriptor string of the entity (class, interface, array class,
primitive type, or
void) represented by this Class object. |
boolean |
desiredAssertionStatus() |
Returns the assertion status that would be assigned to this
class if it were to be initialized at the time this method is invoked.
|
static Class<?> |
forName(Module module,
String name) |
Returns the
Class with the given
binary name in the given module. |
static Class<?> |
forName(String className) |
Returns the
Class object associated with the class or
interface with the given string name. |
static Class<?> |
forName(String name,
boolean initialize,
ClassLoader loader) |
Returns the
Class object associated with the class or
interface with the given string name, using the given class loader. |
AnnotatedType[] |
getAnnotatedInterfaces() |
Returns an array of
AnnotatedType objects that represent the use
of types to specify superinterfaces of the entity represented by this
Class object. |
AnnotatedType |
getAnnotatedSuperclass() |
Returns an
AnnotatedType object that represents the use of a
type to specify the superclass of the entity represented by this
Class object. |
<A extends Annotation> |
getAnnotation(Class<A> annotationClass) |
Returns this element's annotation for the specified type if
such an annotation is present, else null.
|
Annotation[] |
getAnnotations() |
Returns annotations that are present on this element.
|
<A extends Annotation> |
getAnnotationsByType(Class<A> annotationClass) |
Returns annotations that are associated with this element.
|
String |
getCanonicalName() |
Returns the canonical name of the underlying class as
defined by The Java Language Specification.
|
Class<?>[] |
getClasses() |
Returns an array containing
Class objects representing all
the public classes and interfaces that are members of the class
represented by this Class object. |
ClassLoader |
getClassLoader() |
Returns the class loader for the class.
|
Class<?> |
getComponentType() |
Returns the
Class representing the component type of an
array. |
Constructor<T> |
getConstructor(Class<?>... parameterTypes) |
Returns a
Constructor object that reflects the specified
public constructor of the class represented by this Class
object. |
Constructor<?>[] |
getConstructors() |
Returns an array containing
Constructor objects reflecting
all the public constructors of the class represented by this
Class object. |
<A extends Annotation> |
getDeclaredAnnotation(Class<A> annotationClass) |
Returns this element's annotation for the specified type if
such an annotation is directly present, else null.
|
Annotation[] |
getDeclaredAnnotations() |
Returns annotations that are directly present on this element.
|
<A extends Annotation> |
getDeclaredAnnotationsByType(Class<A> annotationClass) |
Returns this element's annotation(s) for the specified type if
such annotations are either directly present or
indirectly present.
|
Class<?>[] |
getDeclaredClasses() |
Returns an array of
Class objects reflecting all the
classes and interfaces declared as members of the class represented by
this Class object. |
Constructor<T> |
getDeclaredConstructor(Class<?>... parameterTypes) |
Returns a
Constructor object that reflects the specified
constructor of the class or interface represented by this
Class object. |
Constructor<?>[] |
getDeclaredConstructors() |
Returns an array of
Constructor objects reflecting all the
constructors declared by the class represented by this
Class object. |
Field |
getDeclaredField(String name) |
Returns a
Field object that reflects the specified declared
field of the class or interface represented by this Class
object. |
Field[] |
getDeclaredFields() |
Returns an array of
Field objects reflecting all the fields
declared by the class or interface represented by this
Class object. |
Method |
getDeclaredMethod(String name,
Class<?>... parameterTypes) |
Returns a
Method object that reflects the specified
declared method of the class or interface represented by this
Class object. |
Method[] |
getDeclaredMethods() |
Returns an array containing
Method objects reflecting all the
declared methods of the class or interface represented by this
Class object, including public, protected, default (package)
access, and private methods, but excluding inherited methods. |
Class<?> |
getDeclaringClass() |
If the class or interface represented by this
Class object
is a member of another class, returns the Class object
representing the class in which it was declared. |
Class<?> |
getEnclosingClass() |
Returns the immediately enclosing class of the underlying
class.
|
Constructor<?> |
getEnclosingConstructor() |
If this
Class object represents a local or anonymous
class within a constructor, returns a Constructor object representing
the immediately enclosing constructor of the underlying
class. |
Method |
getEnclosingMethod() |
If this
Class object represents a local or anonymous
class within a method, returns a Method object representing the
immediately enclosing method of the underlying class. |
T[] |
getEnumConstants() |
Returns the elements of this enum class or null if this
Class object does not represent an enum type.
|
Field |
getField(String name) |
Returns a
Field object that reflects the specified public member
field of the class or interface represented by this Class
object. |
Field[] |
getFields() |
Returns an array containing
Field objects reflecting all
the accessible public fields of the class or interface represented by
this Class object. |
Type[] |
getGenericInterfaces() |
Returns the
Types representing the interfaces
directly implemented by the class or interface represented by
this Class object. |
Type |
getGenericSuperclass() |
Returns the
Type representing the direct superclass of
the entity (class, interface, primitive type or void) represented by
this Class object. |
Class<?>[] |
getInterfaces() |
Returns the interfaces directly implemented by the class or interface
represented by this
Class object. |
Method |
getMethod(String name,
Class<?>... parameterTypes) |
Returns a
Method object that reflects the specified public
member method of the class or interface represented by this
Class object. |
Method[] |
getMethods() |
Returns an array containing
Method objects reflecting all the
public methods of the class or interface represented by this
Class object, including those declared by the class or interface and
those inherited from superclasses and superinterfaces. |
int |
getModifiers() |
Returns the Java language modifiers for this class or interface, encoded
in an integer.
|
Module |
getModule() |
Returns the module that this class or interface is a member of.
|
String |
getName() |
Returns the name of the entity (class, interface, array class,
primitive type, or void) represented by this
Class object. |
Class<?> |
getNestHost() |
Returns the nest host of the nest to which the class
or interface represented by this
Class object belongs. |
Class<?>[] |
getNestMembers() |
Returns an array containing
Class objects representing all the
classes and interfaces that are members of the nest to which the class
or interface represented by this Class object belongs. |
Package |
getPackage() |
Gets the package of this class.
|
String |
getPackageName() |
Returns the fully qualified package name.
|
ProtectionDomain |
getProtectionDomain() |
Returns the
ProtectionDomain of this class. |
RecordComponent[] |
getRecordComponents() |
Associated with records, a preview feature of the Java language. Returns an array of RecordComponent objects representing all the
record components of this record class, or null if this class is
not a record class. |
URL |
getResource(String name) |
Finds a resource with a given name.
|
InputStream |
getResourceAsStream(String name) |
Finds a resource with a given name.
|
Object[] |
getSigners() |
Gets the signers of this class.
|
String |
getSimpleName() |
Returns the simple name of the underlying class as given in the
source code.
|
Class<? super T> |
getSuperclass() |
Returns the
Class representing the direct superclass of the
entity (class, interface, primitive type or void) represented by
this Class. |
String |
getTypeName() |
Return an informative string for the name of this type.
|
TypeVariable<Class<T>>[] |
getTypeParameters() |
Returns an array of
TypeVariable objects that represent the
type variables declared by the generic declaration represented by this
GenericDeclaration object, in declaration order. |
boolean |
isAnnotation() |
Returns true if this
Class object represents an annotation
type. |
boolean |
isAnnotationPresent(Class<? extends Annotation> annotationClass) |
Returns true if an annotation for the specified type
is present on this element, else false.
|
boolean |
isAnonymousClass() |
Returns
true if and only if the underlying class
is an anonymous class. |
boolean |
isArray() |
Determines if this
Class object represents an array class. |
boolean |
isAssignableFrom(Class<?> cls) |
Determines if the class or interface represented by this
Class object is either the same as, or is a superclass or
superinterface of, the class or interface represented by the specified
Class parameter. |
boolean |
isEnum() |
Returns true if and only if this class was declared as an enum in the
source code.
|
boolean |
isHidden() |
Returns
true if and only if the underlying class is a hidden class. |
boolean |
isInstance(Object obj) |
Determines if the specified
Object is assignment-compatible
with the object represented by this Class. |
boolean |
isInterface() |
Determines if this
Class object represents an
interface type. |
boolean |
isLocalClass() |
Returns
true if and only if the underlying class
is a local class. |
boolean |
isMemberClass() |
Returns
true if and only if the underlying class
is a member class. |
boolean |
isNestmateOf(Class<?> c) |
Determines if the given
Class is a nestmate of the
class or interface represented by this Class object. |
boolean |
isPrimitive() |
Determines if the specified
Class object represents a
primitive type. |
boolean |
isRecord() |
Associated with records, a preview feature of the Java language. Returns true if and only if this class is a record class. |
boolean |
isSealed() |
*
Associated with sealed classes, a preview feature of the Java language. Returns true if and only if this Class object represents a sealed class or interface. |
boolean |
isSynthetic() |
Returns
true if and only if this class has the synthetic modifier
bit set. |
T |
newInstance() |
Deprecated.
This method propagates any exception thrown by the
nullary constructor, including a checked exception.
|
ClassDesc[] |
permittedSubclasses() |
Associated with sealed classes, a preview feature of the Java language. Returns an array containing ClassDesc objects representing all the
direct subclasses or direct implementation classes permitted to extend or
implement this class or interface if it is sealed. |
String |
toGenericString() |
Returns a string describing this
Class, including
information about modifiers and type parameters. |
String |
toString() |
Converts the object to a string.
|
getName.
If this Class object represents a primitive type,
this method returns the name of the primitive type. If
this Class object represents void this method returns
"void". If this Class object represents an array type,
this method returns "class " followed by getName.Class, including
information about modifiers and type parameters.
The string is formatted as a list of type modifiers, if any,
followed by the kind of type (empty string for primitive types
and class, enum, interface,
@interface, or record as appropriate), followed
by the type's name, followed by an angle-bracketed
comma-separated list of the type's type parameters, if any,
including informative bounds on the type parameters, if any.
A space is used to separate modifiers from one another and to
separate any modifiers from the kind of type. The modifiers
occur in canonical order. If there are no type parameters, the
type parameter list is elided.
For an array type, the string starts with the type name,
followed by an angle-bracketed comma-separated list of the
type's type parameters, if any, followed by a sequence of
[] characters, one set of brackets per dimension of
the array.
Note that since information about the runtime representation of a type is being generated, modifiers not present on the originating source code or illegal on the originating source code may be present.
Class, including
information about modifiers and type parametersClass object associated with the class or
interface with the given string name. Invoking this method is
equivalent to:
Class.forName(className, true, currentLoader)
where currentLoader denotes the defining class loader of
the current class.
For example, the following code fragment returns the
runtime Class descriptor for the class named
java.lang.Thread:
Class t = Class.forName("java.lang.Thread")
A call to forName("X") causes the class named
X to be initialized.
className - the fully qualified name of the desired class.Class object for the class with the
specified name.LinkageError - if the linkage failsExceptionInInitializerError - if the initialization provoked
by this method failsClassNotFoundException - if the class cannot be locatedClass object associated with the class or
interface with the given string name, using the given class loader.
Given the fully qualified name for a class or interface (in the same
format returned by getName) this method attempts to
locate and load the class or interface. The specified class
loader is used to load the class or interface. If the parameter
loader is null, the class is loaded through the bootstrap
class loader. The class is initialized only if the
initialize parameter is true and if it has
not been initialized earlier.
If name denotes a primitive type or void, an attempt
will be made to locate a user-defined class in the unnamed package whose
name is name. Therefore, this method cannot be used to
obtain any of the Class objects representing primitive
types or void.
If name denotes an array class, the component type of
the array class is loaded but not initialized.
For example, in an instance method the expression:
Class.forName("Foo")
is equivalent to:
Class.forName("Foo", true, this.getClass().getClassLoader())
Note that this method throws errors related to loading, linking
or initializing as specified in Sections 12.2, 12.3, and 12.4 of The Java Language
Specification.
Note that this method does not check whether the requested class
is accessible to its caller.name - fully qualified name of the desired classinitialize - if true the class will be initialized
(which implies linking). See Section 12.4 of The Java Language
Specification.loader - class loader from which the class must be loadedLinkageError - if the linkage failsExceptionInInitializerError - if the initialization provoked
by this method failsClassNotFoundException - if the class cannot be located by
the specified class loaderSecurityException - if a security manager is present, and the loader is
null, and the caller's class loader is not
null, and the caller does not have the
RuntimePermission("getClassLoader")forName(String),
ClassLoaderClass with the given
binary name in the given module.
This method attempts to locate and load the class or interface.
It does not link the class, and does not run the class initializer.
If the class is not found, this method returns null.
If the class loader of the given module defines other modules and
the given name is a class defined in a different module, this method
returns null after the class is loaded.
This method does not check whether the requested class is accessible to its caller.
null on failure rather than
throwing a ClassNotFoundException, as is done by
the forName(String, boolean, ClassLoader) method.
The security check is a stack-based permission check if the caller
loads a class in another module.module - A modulename - The binary name
of the classClass object of the given name defined in the given module;
null if not found.NullPointerException - if the given module or name is nullLinkageError - if the linkage failsSecurityException - RuntimePermission("getClassLoader") permission is denied; orModuleReader.open(String) to read the bytes of a class file
in a module.Constructor.newInstance method avoids this problem by wrapping
any exception thrown by the constructor in a (checked) InvocationTargetException.
The call
clazz.newInstance()
can be replaced by
clazz.getDeclaredConstructor().newInstance()
The latter sequence of calls is inferred to be able to throw
the additional exception types InvocationTargetException and NoSuchMethodException. Both of these exception types are
subclasses of ReflectiveOperationException.Class
object. The class is instantiated as if by a new
expression with an empty argument list. The class is initialized if it
has not already been initialized.IllegalAccessException - if the class or its nullary
constructor is not accessible.InstantiationException - if this Class represents an abstract class,
an interface, an array class, a primitive type, or void;
or if the class has no nullary constructor;
or if the instantiation fails for some other reason.ExceptionInInitializerError - if the initialization
provoked by this method fails.SecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Object is assignment-compatible
with the object represented by this Class. This method is
the dynamic equivalent of the Java language instanceof
operator. The method returns true if the specified
Object argument is non-null and can be cast to the
reference type represented by this Class object without
raising a ClassCastException. It returns false
otherwise.
Specifically, if this Class object represents a
declared class, this method returns true if the specified
Object argument is an instance of the represented class (or
of any of its subclasses); it returns false otherwise. If
this Class object represents an array class, this method
returns true if the specified Object argument
can be converted to an object of the array class by an identity
conversion or by a widening reference conversion; it returns
false otherwise. If this Class object
represents an interface, this method returns true if the
class or any superclass of the specified Object argument
implements this interface; it returns false otherwise. If
this Class object represents a primitive type, this method
returns false.
obj - the object to checkobj is an instance of this classClass object is either the same as, or is a superclass or
superinterface of, the class or interface represented by the specified
Class parameter. It returns true if so;
otherwise it returns false. If this Class
object represents a primitive type, this method returns
true if the specified Class parameter is
exactly this Class object; otherwise it returns
false.
Specifically, this method tests whether the type represented by the
specified Class parameter can be converted to the type
represented by this Class object via an identity conversion
or via a widening reference conversion. See The Java Language
Specification, sections 5.1.1 and 5.1.4,
for details.
cls - the Class object to be checkedboolean value indicating whether objects of the
type cls can be assigned to objects of this classNullPointerException - if the specified Class parameter is
null.Class object represents an
interface type.true if this Class object represents an interface;
false otherwise.Class object represents an array class.isArray in interface TypeDescriptor.OfField<T>true if this Class object represents an array class;
false otherwise.Class object represents a
primitive type.
There are nine predefined Class objects to represent
the eight primitive types and void. These are created by the Java
Virtual Machine, and have the same names as the primitive types that
they represent, namely boolean, byte,
char, short, int,
long, float, and double.
These objects may only be accessed via the following public static
final variables, and are the only Class objects for which
this method returns true.
isPrimitive in interface TypeDescriptor.OfField<T>Boolean.TYPE,
Character.TYPE,
Byte.TYPE,
Short.TYPE,
Integer.TYPE,
Long.TYPE,
Float.TYPE,
Double.TYPE,
Void.TYPEClass object represents an annotation
type. Note that if this method returns true, isInterface()
would also return true, as all annotation types are also interfaces.true if this Class object represents an annotation
type; false otherwisetrue if and only if this class has the synthetic modifier
bit set.true if and only if this class has the synthetic modifier bit setClassFile StructureClass object.
If this Class object represents a class or interface,
not an array class, then:
N + '/' + <suffix>
where N is the binary name
indicated by the class file passed to
Lookup::defineHiddenClass, and <suffix> is an unqualified name.
If this Class object represents an array class, then
the result is a string consisting of one or more '[' characters
representing the depth of the array nesting, followed by the element
type as encoded using the following table:
Element types and encodings Element Type Encoding booleanZbyteBcharCclass or interface with binary name N LN;doubleDfloatFintIlongJshortS
If this Class object represents a primitive type or void,
then the result is a string with the same spelling as the Java language
keyword which corresponds to the primitive type or void.
Examples:
String.class.getName()
returns "java.lang.String"
byte.class.getName()
returns "byte"
(new Object[3]).getClass().getName()
returns "[Ljava.lang.Object;"
(new int[3][4][5][6][7][8][9]).getClass().getName()
returns "[[[[[[[I"
Class object.If this Class object
represents a primitive type or void, null is returned.
Class object.SecurityException - if a security manager is present, and the caller's class loader
is not null and is not the same as or an ancestor of the
class loader for the class whose class loader is requested,
and the caller does not have the
RuntimePermission("getClassLoader")ClassLoader,
SecurityManager.checkPermission(java.security.Permission),
RuntimePermissionModule for the element type. If this class represents a
primitive type or void, then the Module object for the
java.base module is returned.
If this class is in an unnamed module then the unnamed Module of the class
loader for this class is returned.TypeVariable objects that represent the
type variables declared by the generic declaration represented by this
GenericDeclaration object, in declaration order. Returns an
array of length 0 if the underlying generic declaration declares no type
variables.getTypeParameters in interface GenericDeclarationTypeVariable objects that represent
the type variables declared by this generic declarationGenericSignatureFormatError - if the generic
signature of this generic declaration does not conform to
the format specified in section 4.7.9 of
The Java Virtual Machine SpecificationClass representing the direct superclass of the
entity (class, interface, primitive type or void) represented by
this Class. If this Class represents either the
Object class, an interface, a primitive type, or void, then
null is returned. If this Class object represents an array class
then the Class object representing the Object class is
returned.Class objectType representing the direct superclass of
the entity (class, interface, primitive type or void) represented by
this Class object.
If the superclass is a parameterized type, the Type
object returned must accurately reflect the actual type
arguments used in the source code. The parameterized type
representing the superclass is created if it had not been
created before. See the declaration of ParameterizedType for the
semantics of the creation process for parameterized types. If
this Class object represents either the Object
class, an interface, a primitive type, or void, then null is
returned. If this Class object represents an array class
then the Class object representing the Object class is
returned.
Class objectGenericSignatureFormatError - if the generic
class signature does not conform to the format specified in
section 4.7.9 of The Java Virtual
Machine SpecificationTypeNotPresentException - if the generic superclass
refers to a non-existent type declarationMalformedParameterizedTypeException - if the
generic superclass refers to a parameterized type that cannot be
instantiated for any reasonIf this class represents an array type, a primitive type or void,
this method returns null.
If this class is a top level class, then this method returns the fully qualified name of the package that the class is a member of, or the empty string if the class is in an unnamed package.
If this class is a member class, then this method is equivalent to
invoking getPackageName() on the enclosing class.
If this class is a local class or an anonymous class, then this method is equivalent to
invoking getPackageName() on the declaring class of the enclosing method or
enclosing constructor.
If this class represents an array type then this method returns the
package name of the element type. If this class represents a primitive
type or void then the package name "java.lang" is returned.
Class object.
If this Class object represents a class, the return value is an array
containing objects representing all interfaces directly implemented by
the class. The order of the interface objects in the array corresponds
to the order of the interface names in the implements clause of
the declaration of the class represented by this Class object. For example,
given the declaration:
class Shimmer implements FloorWax, DessertTopping { ... }
suppose the value of s is an instance of
Shimmer; the value of the expression:
s.getClass().getInterfaces()[0]
is the Class object that represents interface
FloorWax; and the value of:
s.getClass().getInterfaces()[1]
is the Class object that represents interface
DessertTopping.
If this Class object represents an interface, the array contains objects
representing all interfaces directly extended by the interface. The
order of the interface objects in the array corresponds to the order of
the interface names in the extends clause of the declaration of
the interface represented by this Class object.
If this Class object represents a class or interface that implements no
interfaces, the method returns an array of length 0.
If this Class object represents a primitive type or void, the method
returns an array of length 0.
If this Class object represents an array type, the
interfaces Cloneable and java.io.Serializable are
returned in that order.
Types representing the interfaces
directly implemented by the class or interface represented by
this Class object.
If a superinterface is a parameterized type, the
Type object returned for it must accurately reflect
the actual type arguments used in the source code. The
parameterized type representing each superinterface is created
if it had not been created before. See the declaration of
ParameterizedType
for the semantics of the creation process for parameterized
types.
If this Class object represents a class, the return value is an array
containing objects representing all interfaces directly implemented by
the class. The order of the interface objects in the array corresponds
to the order of the interface names in the implements clause of
the declaration of the class represented by this Class object.
If this Class object represents an interface, the array contains objects
representing all interfaces directly extended by the interface. The
order of the interface objects in the array corresponds to the order of
the interface names in the extends clause of the declaration of
the interface represented by this Class object.
If this Class object represents a class or interface that implements no
interfaces, the method returns an array of length 0.
If this Class object represents a primitive type or void, the method
returns an array of length 0.
If this Class object represents an array type, the
interfaces Cloneable and java.io.Serializable are
returned in that order.
GenericSignatureFormatError - if the generic class signature does not conform to the
format specified in section 4.7.9 of The
Java Virtual Machine SpecificationTypeNotPresentException - if any of the generic
superinterfaces refers to a non-existent type declarationMalformedParameterizedTypeException - if any of the generic superinterfaces refer to a parameterized
type that cannot be instantiated for any reasonClass representing the component type of an
array. If this class does not represent an array class this method
returns null.Class representing the component type of this
class if this class is an arrayArraypublic, protected,
private, final, static,
abstract and interface; they should be decoded
using the methods of class Modifier.
If the underlying class is an array class, then its
public, private and protected
modifiers are the same as those of its component type. If this
Class object represents a primitive type or void, its
public modifier is always true, and its
protected and private modifiers are always
false. If this Class object represents an array class, a
primitive type or void, then its final modifier is always
true and its interface modifier is always
false. The values of its other modifiers are not determined
by this specification.
The modifier encodings are defined in section 4.1 of The Java Virtual Machine Specification.
int representing the modifiers for this classModifierClass object represents
a primitive type or void.Class object represents a local or anonymous
class within a method, returns a Method object representing the
immediately enclosing method of the underlying class. Returns
null otherwise.
In particular, this method returns null if the underlying
class is a local or anonymous class immediately enclosed by a type
declaration, instance initializer or static initializer.null.SecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the methods within the enclosing class
s.checkPackageAccess() denies access to the package
of the enclosing class
Class object represents a local or anonymous
class within a constructor, returns a Constructor object representing
the immediately enclosing constructor of the underlying
class. Returns null otherwise. In particular, this
method returns null if the underlying class is a local
or anonymous class immediately enclosed by a type declaration,
instance initializer or static initializer.null.SecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the constructors within the enclosing class
s.checkPackageAccess() denies access to the package
of the enclosing class
Class object
is a member of another class, returns the Class object
representing the class in which it was declared. This method returns
null if this class or interface is not a member of any other class. If
this Class object represents an array class, a primitive
type, or void,then this method returns null.SecurityException - If a security manager, s, is present and the caller's
class loader is not the same as or an ancestor of the class
loader for the declaring class and invocation of s.checkPackageAccess()
denies access to the package of the declaring classnull.SecurityException - If a security manager, s, is present and the caller's
class loader is not the same as or an ancestor of the class
loader for the enclosing class and invocation of s.checkPackageAccess()
denies access to the package of the enclosing classThe simple name of an array is the simple name of the component type with "[]" appended. In particular the simple name of an array whose component type is anonymous is "[]".
getTypeName in interface Typenull if the underlying class does not have a canonical
name. Classes without canonical names include:
null otherwise.true if and only if the underlying class
is an anonymous class.true if and only if this class is an anonymous class.true if and only if the underlying class
is a local class.true if and only if this class is a local class.true if and only if the underlying class
is a member class.true if and only if this class is a member class.Class objects representing all
the public classes and interfaces that are members of the class
represented by this Class object. This includes public
class and interface members inherited from superclasses and public class
and interface members declared by the class. This method returns an
array of length 0 if this Class object has no public member
classes or interfaces. This method also returns an array of length 0 if
this Class object represents a primitive type, an array
class, or void.Class objects representing the public
members of this classSecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Field objects reflecting all
the accessible public fields of the class or interface represented by
this Class object.
If this Class object represents a class or interface with
no accessible public fields, then this method returns an array of length
0.
If this Class object represents a class, then this method
returns the public fields of the class and of all its superclasses and
superinterfaces.
If this Class object represents an interface, then this
method returns the fields of the interface and of all its
superinterfaces.
If this Class object represents an array type, a primitive
type, or void, then this method returns an array of length 0.
The elements in the returned array are not sorted and are not in any particular order.
Field objects representing the
public fieldsSecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Method objects reflecting all the
public methods of the class or interface represented by this
Class object, including those declared by the class or interface and
those inherited from superclasses and superinterfaces.
If this Class object represents an array type, then the
returned array has a Method object for each of the public
methods inherited by the array type from Object. It does not
contain a Method object for clone().
If this Class object represents an interface then the
returned array does not contain any implicitly declared methods from
Object. Therefore, if no methods are explicitly declared in
this interface or any of its superinterfaces then the returned array
has length 0. (Note that a Class object which represents a class
always has public methods, inherited from Object.)
The returned array never contains methods with names "<init>"
or "<clinit>".
The elements in the returned array are not sorted and are not in any particular order.
Generally, the result is computed as with the following 4 step algorithm.
Let C be the class or interface represented by this Class object:
getDeclaredMethods() and filtered to include only public
methods.Object, then include the result
of invoking this algorithm recursively on the superclass of C.Method objects representing the
public methods of this classSecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Constructor objects reflecting
all the public constructors of the class represented by this
Class object. An array of length 0 is returned if the
class has no public constructors, or if the class is an array class, or
if the class reflects a primitive type or void.
Constructor<T> objects (that is an array of constructors from
this class), the return type of this method is
Constructor<?>[] and not Constructor<T>[] as
might be expected. This less informative return type is
necessary since after being returned from this method, the
array could be modified to hold Constructor objects for
different classes, which would violate the type guarantees of
Constructor<T>[].Constructor objects representing the
public constructors of this classSecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Field object that reflects the specified public member
field of the class or interface represented by this Class
object. The name parameter is a String specifying the
simple name of the desired field.
The field to be reflected is determined by the algorithm that
follows. Let C be the class or interface represented by this Class object:
NoSuchFieldException
is thrown. If this Class object represents an array type, then this
method does not find the length field of the array type.
name - the field nameField object of this class specified by
nameNoSuchFieldException - if a field with the specified name is
not found.NullPointerException - if name is nullSecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Method object that reflects the specified public
member method of the class or interface represented by this
Class object. The name parameter is a
String specifying the simple name of the desired method. The
parameterTypes parameter is an array of Class
objects that identify the method's formal parameter types, in declared
order. If parameterTypes is null, it is
treated as if it were an empty array.
If this Class object represents an array type, then this
method finds any public method inherited by the array type from
Object except method clone().
If this Class object represents an interface then this
method does not find any implicitly declared method from
Object. Therefore, if no methods are explicitly declared in
this interface or any of its superinterfaces, then this method does not
find any method.
This method does not find any method with name "<init>" or
"<clinit>".
Generally, the method to be reflected is determined by the 4 step
algorithm that follows.
Let C be the class or interface represented by this Class object:
getDeclaredMethods() and filtered to include only public
methods that match given name and parameterTypesObject, then include the result
of invoking this algorithm recursively on the superclass of C.isAssignableFrom(java.lang.Class<?>)(S.class).
name - the name of the methodparameterTypes - the list of parametersMethod object that matches the specified
name and parameterTypesNoSuchMethodException - if a matching method is not found
or if the name is "<init>"or "<clinit>".NullPointerException - if name is nullSecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Constructor object that reflects the specified
public constructor of the class represented by this Class
object. The parameterTypes parameter is an array of
Class objects that identify the constructor's formal
parameter types, in declared order.
If this Class object represents an inner class
declared in a non-static context, the formal parameter types
include the explicit enclosing instance as the first parameter.
The constructor to reflect is the public constructor of the class
represented by this Class object whose formal parameter
types match those specified by parameterTypes.
parameterTypes - the parameter arrayConstructor object of the public constructor that
matches the specified parameterTypesNoSuchMethodException - if a matching method is not found.SecurityException - If a security manager, s, is present and
the caller's class loader is not the same as or an
ancestor of the class loader for the current class and
invocation of s.checkPackageAccess() denies access to the package
of this class.Class objects reflecting all the
classes and interfaces declared as members of the class represented by
this Class object. This includes public, protected, default
(package) access, and private classes and interfaces declared by the
class, but excludes inherited classes and interfaces. This method
returns an array of length 0 if the class declares no classes or
interfaces as members, or if this Class object represents a
primitive type, an array class, or void.Class objects representing all the
declared members of this classSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared classes within this class
s.checkPackageAccess() denies access to the package
of this class
Field objects reflecting all the fields
declared by the class or interface represented by this
Class object. This includes public, protected, default
(package) access, and private fields, but excludes inherited fields.
If this Class object represents a class or interface with no
declared fields, then this method returns an array of length 0.
If this Class object represents an array type, a primitive
type, or void, then this method returns an array of length 0.
The elements in the returned array are not sorted and are not in any particular order.
Field objects representing all the
declared fields of this classSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared fields within this class
s.checkPackageAccess() denies access to the package
of this class
RecordComponent objects representing all the
record components of this record class, or null if this class is
not a record class.
The components are returned in the same order that they are declared
in the record header. The array is empty if this record class has no
components. If the class is not a record class, that is isRecord() returns false, then this method returns null.
Conversely, if isRecord() returns true, then this method
returns a non-null value.
RecordComponent objects representing all the
record components of this record class, or null if this
class is not a record classSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared methods within this class
s.checkPackageAccess() denies access to the package
of this class
Method objects reflecting all the
declared methods of the class or interface represented by this
Class object, including public, protected, default (package)
access, and private methods, but excluding inherited methods.
If this Class object represents a type that has multiple
declared methods with the same name and parameter types, but different
return types, then the returned array has a Method object for
each such method.
If this Class object represents a type that has a class
initialization method <clinit>, then the returned array does
not have a corresponding Method object.
If this Class object represents a class or interface with no
declared methods, then the returned array has length 0.
If this Class object represents an array type, a primitive
type, or void, then the returned array has length 0.
The elements in the returned array are not sorted and are not in any particular order.
Method objects representing all the
declared methods of this classSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared methods within this class
s.checkPackageAccess() denies access to the package
of this class
Constructor objects reflecting all the
constructors declared by the class represented by this
Class object. These are public, protected, default
(package) access, and private constructors. The elements in the array
returned are not sorted and are not in any particular order. If the
class has a default constructor, it is included in the returned array.
This method returns an array of length 0 if this Class
object represents an interface, a primitive type, an array class, or
void.
See The Java Language Specification, section 8.2.
Constructor objects representing all the
declared constructors of this classSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared constructors within this class
s.checkPackageAccess() denies access to the package
of this class
Field object that reflects the specified declared
field of the class or interface represented by this Class
object. The name parameter is a String that specifies
the simple name of the desired field.
If this Class object represents an array type, then this
method does not find the length field of the array type.
name - the name of the fieldField object for the specified field in this
classNoSuchFieldException - if a field with the specified name is
not found.NullPointerException - if name is nullSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared field
s.checkPackageAccess() denies access to the package
of this class
Method object that reflects the specified
declared method of the class or interface represented by this
Class object. The name parameter is a
String that specifies the simple name of the desired
method, and the parameterTypes parameter is an array of
Class objects that identify the method's formal parameter
types, in declared order. If more than one method with the same
parameter types is declared in a class, and one of these methods has a
return type that is more specific than any of the others, that method is
returned; otherwise one of the methods is chosen arbitrarily. If the
name is "<init>"or "<clinit>" a NoSuchMethodException
is raised.
If this Class object represents an array type, then this
method does not find the clone() method.
name - the name of the methodparameterTypes - the parameter arrayMethod object for the method of this class
matching the specified name and parametersNoSuchMethodException - if a matching method is not found.NullPointerException - if name is nullSecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared method
s.checkPackageAccess() denies access to the package
of this class
Constructor object that reflects the specified
constructor of the class or interface represented by this
Class object. The parameterTypes parameter is
an array of Class objects that identify the constructor's
formal parameter types, in declared order.
If this Class object represents an inner class
declared in a non-static context, the formal parameter types
include the explicit enclosing instance as the first parameter.parameterTypes - the parameter arrayConstructor object for the constructor with the
specified parameter listNoSuchMethodException - if a matching method is not found.SecurityException - If a security manager, s, is present and any of the
following conditions is met:
s.checkPermission method with
RuntimePermission("accessDeclaredMembers")
denies access to the declared constructor
s.checkPackageAccess() denies access to the package
of this class
If this class is in a named Module then this method
will attempt to find the resource in the module. This is done by
delegating to the module's class loader findResource(String,String)
method, invoking it with the module name and the absolute name of the
resource. Resources in named modules are subject to the rules for
encapsulation specified in the Module getResourceAsStream method and so this
method returns null when the resource is a
non-".class" resource in a package that is not open to the
caller's module.
Otherwise, if this class is not in a named module then the rules for
searching resources associated with a given class are implemented by the
defining class loader of the class. This method
delegates to this Class object's class loader.
If this Class object was loaded by the bootstrap class loader,
the method delegates to ClassLoader.getSystemResourceAsStream(java.lang.String).
Before delegation, an absolute resource name is constructed from the given resource name using this algorithm:
name begins with a '/'
('\u002f'), then the absolute name of the resource is the
portion of the name following the '/'.
modified_package_name/name
Where the modified_package_name is the package name of this
object with '/' substituted for '.'
('\u002e').
name - name of the desired resourceInputStream object; null if no
resource with this name is found, the resource is in a package
that is not open to at
least the caller module, or access to the resource is denied
by the security manager.NullPointerException - If name is nullModule.getResourceAsStream(String) If this class is in a named Module then this method
will attempt to find the resource in the module. This is done by
delegating to the module's class loader findResource(String,String)
method, invoking it with the module name and the absolute name of the
resource. Resources in named modules are subject to the rules for
encapsulation specified in the Module getResourceAsStream method and so this
method returns null when the resource is a
non-".class" resource in a package that is not open to the
caller's module.
Otherwise, if this class is not in a named module then the rules for
searching resources associated with a given class are implemented by the
defining class loader of the class. This method
delegates to this Class object's class loader.
If this Class object was loaded by the bootstrap class loader,
the method delegates to ClassLoader.getSystemResource(java.lang.String).
Before delegation, an absolute resource name is constructed from the given resource name using this algorithm:
name begins with a '/'
('\u002f'), then the absolute name of the resource is the
portion of the name following the '/'.
modified_package_name/name
Where the modified_package_name is the package name of this
object with '/' substituted for '.'
('\u002e').
name - name of the desired resourceURL object; null if no resource with
this name is found, the resource cannot be located by a URL, the
resource is in a package that is not
open to at least the caller
module, or access to the resource is denied by the security
manager.NullPointerException - If name is nullProtectionDomain of this class. If there is a
security manager installed, this method first calls the security
manager's checkPermission method with a
RuntimePermission("getProtectionDomain") permission to
ensure it's ok to get the
ProtectionDomain.SecurityException - if a security manager exists and its
checkPermission method doesn't allow
getting the ProtectionDomain.ProtectionDomain,
SecurityManager.checkPermission(java.security.Permission),
RuntimePermissionClassLoader.setClassAssertionStatus(java.lang.String, boolean),
ClassLoader.setPackageAssertionStatus(java.lang.String, boolean),
ClassLoader.setDefaultAssertionStatus(boolean)Enum is not itself an enum type.
Also note that if an enum constant is declared with a class body,
the class of that enum constant object is an anonymous class
and not the class of the declaring enum type. The
Enum.getDeclaringClass() method of an enum constant can
be used to get the class of the enum type declaring the
constant.true if and only if this class is a record class.
The direct superclass of a record
class is java.lang.Record. A record class has (possibly zero)
record components, that is, getRecordComponents() returns a
non-null value.
Note that class Record is not a record type and thus invoking
this method on class Record returns false.
Class object in the order they're
declared, or null if this Class object does not
represent an enum typeClass object.obj - the object to be castClassCastException - if the object is not
null and is not assignable to the type T.Class object to represent a subclass of the class
represented by the specified class object. Checks that the cast
is valid, and throws a ClassCastException if it is not. If
this method succeeds, it always returns a reference to this Class object.
This method is useful when a client needs to "narrow" the type of
a Class object to pass it to an API that restricts the
Class objects that it is willing to accept. A cast would
generate a compile-time warning, as the correctness of the cast
could not be checked at runtime (because generic types are implemented
by erasure).
U - the type to cast this Class object toclazz - the class of the type to cast this Class object toClass object, cast to represent a subclass of
the specified class object.ClassCastException - if this Class object does not
represent a subclass of the specified class (here "subclass" includes
the class itself).Note that any annotation returned by this method is a declaration annotation.
getAnnotation in interface AnnotatedElementA - the type of the annotation to query for and return if presentannotationClass - the Class object corresponding to the
annotation typeNullPointerException - if the given annotation class is nullThe truth value returned by this method is equivalent to:
getAnnotation(annotationClass) != null
isAnnotationPresent in interface AnnotatedElementannotationClass - the Class object corresponding to the
annotation typeNullPointerException - if the given annotation class is nullAnnotatedElement.getAnnotation(Class)
is that this method detects if its argument is a repeatable
annotation type (JLS 9.6), and if so, attempts to find one or
more annotations of that type by "looking through" a container
annotation.
The caller of this method is free to modify the returned array; it will
have no effect on the arrays returned to other callers.
Note that any annotations returned by this method are declaration annotations.
getAnnotationsByType in interface AnnotatedElementA - the type of the annotation to query for and return if presentannotationClass - the Class object corresponding to the
annotation typeNullPointerException - if the given annotation class is nullNote that any annotations returned by this method are declaration annotations.
getAnnotations in interface AnnotatedElementNote that any annotation returned by this method is a declaration annotation.
getDeclaredAnnotation in interface AnnotatedElementA - the type of the annotation to query for and return if directly presentannotationClass - the Class object corresponding to the
annotation typeNullPointerException - if the given annotation class is nullAnnotatedElement.getDeclaredAnnotation(Class) is that this method detects if its
argument is a repeatable annotation type (JLS 9.6), and if so,
attempts to find one or more annotations of that type by "looking
through" a container annotation if one is present.
The caller of this method is free to modify the returned array; it will
have no effect on the arrays returned to other callers.
Note that any annotations returned by this method are declaration annotations.
getDeclaredAnnotationsByType in interface AnnotatedElementA - the type of the annotation to query for and return
if directly or indirectly presentannotationClass - the Class object corresponding to the
annotation typeNullPointerException - if the given annotation class is nullNote that any annotations returned by this method are declaration annotations.
getDeclaredAnnotations in interface AnnotatedElementAnnotatedType object that represents the use of a
type to specify the superclass of the entity represented by this
Class object. (The use of type Foo to specify the superclass
in '... extends Foo' is distinct from the declaration of type
Foo.)
If this Class object represents a type whose declaration
does not explicitly indicate an annotated superclass, then the return
value is an AnnotatedType object representing an element with no
annotations.
If this Class represents either the Object class, an
interface type, an array type, a primitive type, or void, the return
value is null.
AnnotatedType objects that represent the use
of types to specify superinterfaces of the entity represented by this
Class object. (The use of type Foo to specify a
superinterface in '... implements Foo' is distinct from the
declaration of type Foo.)
If this Class object represents a class, the return value is
an array containing objects representing the uses of interface types to
specify interfaces implemented by the class. The order of the objects in
the array corresponds to the order of the interface types used in the
'implements' clause of the declaration of this Class object.
If this Class object represents an interface, the return
value is an array containing objects representing the uses of interface
types to specify interfaces directly extended by the interface. The
order of the objects in the array corresponds to the order of the
interface types used in the 'extends' clause of the declaration of this
Class object.
If this Class object represents a class or interface whose
declaration does not explicitly indicate any annotated superinterfaces,
the return value is an array of length 0.
If this Class object represents either the Object
class, an array type, a primitive type, or void, the return value is an
array of length 0.
Class object belongs.
Every class and interface belongs to exactly one nest.
If the nest host of this class or interface has previously
been determined, then this method returns the nest host.
If the nest host of this class or interface has
not previously been determined, then this method determines the nest
host using the algorithm of JVMS 5.4.4, and returns it.
Often, a class or interface belongs to a nest consisting only of itself,
in which case this method returns this to indicate that the class
or interface is the nest host.
If this Class object represents a primitive type, an array type,
or void, then this method returns this,
indicating that the represented entity belongs to the nest consisting only of
itself, and is the nest host.
SecurityException - If the returned class is not the current class, and
if a security manager, s, is present and the caller's
class loader is not the same as or an ancestor of the class
loader for the returned class and invocation of s.checkPackageAccess()
denies access to the package of the returned classNestHost AttributeNestMembers AttributeClass is a nestmate of the
class or interface represented by this Class object.
Two classes or interfaces are nestmates
if they have the same nest host.c - the class to checktrue if this class and c are members of
the same nest; and false otherwise.Class objects representing all the
classes and interfaces that are members of the nest to which the class
or interface represented by this Class object belongs.
First, this method obtains the nest host,
H, of the nest to which the class or interface represented by
this Class object belongs. The zeroth element of the returned
array is H.
Then, for each class or interface C which is recorded by H
as being a member of its nest, this method attempts to obtain the Class
object for C (using the defining class
loader of the current Class object), and then obtains the
nest host of the nest to which C belongs.
The classes and interfaces which are recorded by H as being members
of its nest, and for which H can be determined as their nest host,
are indicated by subsequent elements of the returned array. The order of
such elements is unspecified. Duplicates are permitted.
If this Class object represents a primitive type, an array type,
or void, then this method returns a single-element array containing
this.
NestMembers
attribute, and not any hidden classes that were added to the nest via
Lookup::defineHiddenClass.SecurityException - If any returned class is not the current class, and
if a security manager, s, is present and the caller's
class loader is not the same as or an ancestor of the class
loader for that returned class and invocation of s.checkPackageAccess()
denies access to the package of that returned classNestHost AttributeNestMembers AttributegetNestHost()void) represented by this Class object.
If this Class object represents a class or interface,
not an array class, then:
ClassDesc::ofDescriptor
with the result descriptor string produces a ClassDesc
describing this class or interface.
where N is the binary name encoded in internal form indicated by the"L" +N+ "." + <suffix> + ";"
class file passed to
Lookup::defineHiddenClass, and <suffix> is an unqualified name.
A hidden class or interface has no nominal descriptor.
The result string is not a type descriptor.
If this Class object represents an array class, then
the result is a string consisting of one or more '[' characters
representing the depth of the array nesting, followed by the
descriptor string of the element type.
ClassDesc::ofDescriptor
with the result descriptor string produces a ClassDesc
describing this array class.
If this Class object represents a primitive type or
void, then the result is a field descriptor string which
is a one-letter code corresponding to a primitive type or void
("B", "C", "D", "F", "I", "J", "S", "Z", "V") (JVMS 4.3.2).
descriptorString in interface TypeDescriptorforName(java.lang.String);
distinct classes which share a common name but have different class loaders
will have identical descriptor strings.Class objectClass, if it describes
an array type, or null otherwise.componentType in interface TypeDescriptor.OfField<T>getComponentType().Class describing the component type, or null
if this Class does not describe an array typeClass for an array type whose component type
is described by this Class.arrayType in interface TypeDescriptor.OfField<T>Class describing the array typeOptional if one cannot be.describeConstable in interface ConstableOptional containing the resulting nominal descriptor,
or an empty Optional if one cannot be constructed.true if and only if the underlying class is a hidden class.true if and only if this class is a hidden class.MethodHandles.Lookup.defineHiddenClass(byte[], boolean, java.lang.invoke.MethodHandles.Lookup.ClassOption...)ClassDesc objects representing all the
direct subclasses or direct implementation classes permitted to extend or
implement this class or interface if it is sealed. The order of such elements
is unspecified. If this Class object represents a primitive type,
void, an array type, or a class or interface that is not sealed,
an empty array is returned.true if and only if this Class object represents a sealed class or interface.
If this Class object represents a primitive type, void, or an array type, this method returns
false.true if and only if this Class object represents a sealed class or interface.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.
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