Class « Class « Reflection

Instances of the class Class represent classes and interfaces. An enum is a kind of class and an annotation is a kind of interface. Every array belongs to a class.

Get Class from class name

Name	Summary
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.

Cast to sub class

Return	Method	Summary
<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.

Cast object to the class or interfacd

Return	Method	Summary
T	cast(Object obj)	Casts an object to the class or interface represented by this Class object.

Get annotations

Return	Method	Summary
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.
<A extends Annotation>A	getAnnotation(Class<A> annotationClass)	Returns this element's annotation for the specified type if such an annotation is present, else null.
Annotation[]	getAnnotations()	Returns all annotations present on this element.
Annotation[]	getDeclaredAnnotations()	Returns all annotations that are directly present on this element.

Find out the name

Return	Method	Summary
String	getCanonicalName()	Returns the canonical name of the underlying class as defined by the Java Language Specification.
String	getName()	Returns the name of the entity (class, interface, array class, primitive type, or void) represented by this Class object, as a String.
String	getSimpleName()	Returns the simple name of the underlying class as given in the source code.

Get all classes contained

Return	Method	Summary
Class<?>[]	getClasses()	Returns an array containing Class objects representing all the public classes and interfaces that are members of the class.
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.

Get the class loader

Return	Method	Summary
ClassLoader	getClassLoader()	Returns the class loader for the class.

Component type of an array

Return	Method	Summary
Class<?>	getComponentType()	Returns the Class representing the component type of an array.

Get the contructors from a class

Return	Method	Summary
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.
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.

Get fields, methods and classes

Return	Method	Summary
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 of Method objects reflecting all the methods declared by the class or interface represented by this Class object.
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.
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 member 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.

Get method and constructor for a inner or local class

Return	Method	Summary
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.

Get enum constants for a Enum

Return	Method	Summary
T[]	getEnumConstants()	Returns the elements of this enum class or null if this Class object does not represent an enum type.

Get fields

Return	Method	Summary
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.

Get interface

Return	Method	Summary
Type[]	getGenericInterfaces()	Returns the Types representing the interfaces directly implemented by the class or interface represented by this object.
Class<?>[]	getInterfaces()	Determines the interfaces implemented by the class or interface represented by this object.

Get super class

Return	Method	Summary
Type	getGenericSuperclass()	Returns the Type representing the direct superclass of the entity (class, interface, primitive type or void) represented by this Class.
Class<? super T>	getSuperclass()	Returns the Class representing the superclass of the entity (class, interface, primitive type or void) represented by this Class.

Get the modifiers

Return	Method	Summary
int	getModifiers()	Returns the Java language modifiers for this class or interface, encoded in an integer.

Get the package

Return	Method	Summary
Package	getPackage()	Gets the package for this class.

Get the ProtectionDomain

Return	Method	Summary
ProtectionDomain	getProtectionDomain()	Returns the ProtectionDomain of this class.

Get resources

Return	Method	Summary
URL	getResource(String name)	Finds a resource with a given name.
InputStream	getResourceAsStream(String name)	Finds a resource with a given name.

Get the signers of this class

Return	Method	Summary
Object[]	getSigners()	Gets the signers of this class.

Get the type parameters

Return	Method	Summary
TypeVariable<Class<T>>[]	getTypeParameters()	Returns an array of TypeVariable objects that represent the type variables declared by the generic declaration.

Check the class type

Return	Method	Summary
boolean	isAnnotation()	is it an annotation type.
boolean	isAnnotationPresent(Class<? extends Annotation> annotationClass)	Is an annotation present.
boolean	isAnonymousClass()	Is it an anonymous class.
boolean	isArray()	Is it an array class.
boolean	isAssignableFrom(Class<?> cls)	Is it assigned from.
boolean	isEnum()	Is it an enum.
boolean	isInstance(Object obj)	Is it instance of another object.
boolean	isInterface()	Is it an interface type.
boolean	isLocalClass()	Is it a local class.
boolean	isMemberClass()	Is it a member class.
boolean	isPrimitive()	Is it a primitive type.
boolean	isSynthetic()	Is it a synthetic class.