java.lang
Class Class<T>

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by java.lang.Class<T>
All Implemented Interfaces:
Serializable sample code for java.io.Serializable definition code for java.io.Serializable , AnnotatedElement sample code for java.lang.reflect.AnnotatedElement definition code for java.lang.reflect.AnnotatedElement , GenericDeclaration sample code for java.lang.reflect.GenericDeclaration definition code for java.lang.reflect.GenericDeclaration , Type sample code for java.lang.reflect.Type definition code for java.lang.reflect.Type

public final class Class<T>
extends Object sample code for java.lang.Object definition code for java.lang.Object
implements Serializable sample code for java.io.Serializable definition code for java.io.Serializable , GenericDeclaration sample code for java.lang.reflect.GenericDeclaration definition code for java.lang.reflect.GenericDeclaration , Type sample code for java.lang.reflect.Type definition code for java.lang.reflect.Type , AnnotatedElement sample code for java.lang.reflect.AnnotatedElement definition code for java.lang.reflect.AnnotatedElement

Instances of the class Class represent classes and interfaces in a running Java application. An enum is a kind of class and an annotation 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 Class objects are constructed automatically by the Java Virtual Machine as classes are loaded and by calls to the defineClass method in the class loader.

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 (JLS Section 15.8.2). For example:

     System.out.println("The name of class Foo is: "+Foo.class.getName());
 

Since:
JDK1.0
See Also:
ClassLoader.defineClass(byte[], int, int) sample code for java.lang.ClassLoader.defineClass(byte[], int, int) definition code for java.lang.ClassLoader.defineClass(byte[], int, int) , Serialized Form

Method Summary
<U> Class sample code for java.lang.Class definition code for java.lang.Class <? extends U>
asSubclass sample code for java.lang.Class.asSubclass(java.lang.Class) definition code for java.lang.Class.asSubclass(java.lang.Class) (Class sample code for java.lang.Class definition code for java.lang.Class <U> clazz)
          Casts this Class object to represent a subclass of the class represented by the specified class object.
 T cast sample code for java.lang.Class.cast(java.lang.Object) definition code for java.lang.Class.cast(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  obj)
          Casts an object to the class or interface represented by this Class object.
 boolean desiredAssertionStatus sample code for java.lang.Class.desiredAssertionStatus() definition code for java.lang.Class.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 sample code for java.lang.Class definition code for java.lang.Class <?> forName sample code for java.lang.Class.forName(java.lang.String) definition code for java.lang.Class.forName(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  className)
          Returns the Class object associated with the class or interface with the given string name.
static Class sample code for java.lang.Class definition code for java.lang.Class <?> forName sample code for java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) definition code for java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) (String sample code for java.lang.String definition code for java.lang.String  name, boolean initialize, ClassLoader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader  loader)
          Returns the Class object associated with the class or interface with the given string name, using the given class loader.
<A extends Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation >
A
getAnnotation sample code for java.lang.Class.getAnnotation(java.lang.Class) definition code for java.lang.Class.getAnnotation(java.lang.Class) (Class sample code for java.lang.Class definition code for java.lang.Class <A> annotationClass)
          Returns this element's annotation for the specified type if such an annotation is present, else null.
 Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation [] getAnnotations sample code for java.lang.Class.getAnnotations() definition code for java.lang.Class.getAnnotations() ()
          Returns all annotations present on this element.
 String sample code for java.lang.String definition code for java.lang.String getCanonicalName sample code for java.lang.Class.getCanonicalName() definition code for java.lang.Class.getCanonicalName() ()
          Returns the canonical name of the the underlying class as defined by the Java Language Specification.
 Class sample code for java.lang.Class definition code for java.lang.Class [] getClasses sample code for java.lang.Class.getClasses() definition code for java.lang.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 sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader getClassLoader sample code for java.lang.Class.getClassLoader() definition code for java.lang.Class.getClassLoader() ()
          Returns the class loader for the class.
 Class sample code for java.lang.Class definition code for java.lang.Class <?> getComponentType sample code for java.lang.Class.getComponentType() definition code for java.lang.Class.getComponentType() ()
          Returns the Class representing the component type of an array.
 Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor <T> getConstructor sample code for java.lang.Class.getConstructor(java.lang.Class...) definition code for java.lang.Class.getConstructor(java.lang.Class...) (Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
          Returns a Constructor object that reflects the specified public constructor of the class represented by this Class object.
 Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor [] getConstructors sample code for java.lang.Class.getConstructors() definition code for java.lang.Class.getConstructors() ()
          Returns an array containing Constructor objects reflecting all the public constructors of the class represented by this Class object.
 Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation [] getDeclaredAnnotations sample code for java.lang.Class.getDeclaredAnnotations() definition code for java.lang.Class.getDeclaredAnnotations() ()
          Returns all annotations that are directly present on this element.
 Class sample code for java.lang.Class definition code for java.lang.Class [] getDeclaredClasses sample code for java.lang.Class.getDeclaredClasses() definition code for java.lang.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 sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor <T> getDeclaredConstructor sample code for java.lang.Class.getDeclaredConstructor(java.lang.Class...) definition code for java.lang.Class.getDeclaredConstructor(java.lang.Class...) (Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
          Returns a Constructor object that reflects the specified constructor of the class or interface represented by this Class object.
 Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor [] getDeclaredConstructors sample code for java.lang.Class.getDeclaredConstructors() definition code for java.lang.Class.getDeclaredConstructors() ()
          Returns an array of Constructor objects reflecting all the constructors declared by the class represented by this Class object.
 Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field getDeclaredField sample code for java.lang.Class.getDeclaredField(java.lang.String) definition code for java.lang.Class.getDeclaredField(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  name)
          Returns a Field object that reflects the specified declared field of the class or interface represented by this Class object.
 Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field [] getDeclaredFields sample code for java.lang.Class.getDeclaredFields() definition code for java.lang.Class.getDeclaredFields() ()
          Returns an array of Field objects reflecting all the fields declared by the class or interface represented by this Class object.
 Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method getDeclaredMethod sample code for java.lang.Class.getDeclaredMethod(java.lang.String, java.lang.Class...) definition code for java.lang.Class.getDeclaredMethod(java.lang.String, java.lang.Class...) (String sample code for java.lang.String definition code for java.lang.String  name, Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
          Returns a Method object that reflects the specified declared method of the class or interface represented by this Class object.
 Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method [] getDeclaredMethods sample code for java.lang.Class.getDeclaredMethods() definition code for java.lang.Class.getDeclaredMethods() ()
          Returns an array of Method objects reflecting all the methods declared by the class or interface represented by this Class object.
 Class sample code for java.lang.Class definition code for java.lang.Class <?> getDeclaringClass sample code for java.lang.Class.getDeclaringClass() definition code for java.lang.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 sample code for java.lang.Class definition code for java.lang.Class <?> getEnclosingClass sample code for java.lang.Class.getEnclosingClass() definition code for java.lang.Class.getEnclosingClass() ()
          Returns the immediately enclosing class of the underlying class.
 Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor <?> getEnclosingConstructor sample code for java.lang.Class.getEnclosingConstructor() definition code for java.lang.Class.getEnclosingConstructor() ()
          If this Class object represents a local or anonymous class within a constructor, returns a Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor object representing the immediately enclosing constructor of the underlying class.
 Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method getEnclosingMethod sample code for java.lang.Class.getEnclosingMethod() definition code for java.lang.Class.getEnclosingMethod() ()
          If this Class object represents a local or anonymous class within a method, returns a Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method object representing the immediately enclosing method of the underlying class.
 T[] getEnumConstants sample code for java.lang.Class.getEnumConstants() definition code for java.lang.Class.getEnumConstants() ()
          Returns the elements of this enum class or null if this Class object does not represent an enum type.
 Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field getField sample code for java.lang.Class.getField(java.lang.String) definition code for java.lang.Class.getField(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  name)
          Returns a Field object that reflects the specified public member field of the class or interface represented by this Class object.
 Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field [] getFields sample code for java.lang.Class.getFields() definition code for java.lang.Class.getFields() ()
          Returns an array containing Field objects reflecting all the accessible public fields of the class or interface represented by this Class object.
 Type sample code for java.lang.reflect.Type definition code for java.lang.reflect.Type [] getGenericInterfaces sample code for java.lang.Class.getGenericInterfaces() definition code for java.lang.Class.getGenericInterfaces() ()
          Returns the Types representing the interfaces directly implemented by the class or interface represented by this object.
 Type sample code for java.lang.reflect.Type definition code for java.lang.reflect.Type getGenericSuperclass sample code for java.lang.Class.getGenericSuperclass() definition code for java.lang.Class.getGenericSuperclass() ()
          Returns the Type representing the direct superclass of the entity (class, interface, primitive type or void) represented by this Class.
 Class sample code for java.lang.Class definition code for java.lang.Class [] getInterfaces sample code for java.lang.Class.getInterfaces() definition code for java.lang.Class.getInterfaces() ()
          Determines the interfaces implemented by the class or interface represented by this object.
 Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method getMethod sample code for java.lang.Class.getMethod(java.lang.String, java.lang.Class...) definition code for java.lang.Class.getMethod(java.lang.String, java.lang.Class...) (String sample code for java.lang.String definition code for java.lang.String  name, Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
          Returns a Method object that reflects the specified public member method of the class or interface represented by this Class object.
 Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method [] getMethods sample code for java.lang.Class.getMethods() definition code for java.lang.Class.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.
 int getModifiers sample code for java.lang.Class.getModifiers() definition code for java.lang.Class.getModifiers() ()
          Returns the Java language modifiers for this class or interface, encoded in an integer.
 String sample code for java.lang.String definition code for java.lang.String getName sample code for java.lang.Class.getName() definition code for java.lang.Class.getName() ()
          Returns the name of the entity (class, interface, array class, primitive type, or void) represented by this Class object, as a String.
 Package sample code for java.lang.Package definition code for java.lang.Package getPackage sample code for java.lang.Class.getPackage() definition code for java.lang.Class.getPackage() ()
          Gets the package for this class.
 ProtectionDomain sample code for java.security.ProtectionDomain definition code for java.security.ProtectionDomain getProtectionDomain sample code for java.lang.Class.getProtectionDomain() definition code for java.lang.Class.getProtectionDomain() ()
          Returns the ProtectionDomain of this class.
 URL sample code for java.net.URL definition code for java.net.URL getResource sample code for java.lang.Class.getResource(java.lang.String) definition code for java.lang.Class.getResource(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  name)
          Finds a resource with a given name.
 InputStream sample code for java.io.InputStream definition code for java.io.InputStream getResourceAsStream sample code for java.lang.Class.getResourceAsStream(java.lang.String) definition code for java.lang.Class.getResourceAsStream(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  name)
          Finds a resource with a given name.
 Object sample code for java.lang.Object definition code for java.lang.Object [] getSigners sample code for java.lang.Class.getSigners() definition code for java.lang.Class.getSigners() ()
          Gets the signers of this class.
 String sample code for java.lang.String definition code for java.lang.String getSimpleName sample code for java.lang.Class.getSimpleName() definition code for java.lang.Class.getSimpleName() ()
          Returns the simple name of the underlying class as given in the source code.
 Class sample code for java.lang.Class definition code for java.lang.Class <? super T> getSuperclass sample code for java.lang.Class.getSuperclass() definition code for java.lang.Class.getSuperclass() ()
          Returns the Class representing the superclass of the entity (class, interface, primitive type or void) represented by this Class.
 TypeVariable sample code for java.lang.reflect.TypeVariable definition code for java.lang.reflect.TypeVariable <Class sample code for java.lang.Class definition code for java.lang.Class <T>>[] getTypeParameters sample code for java.lang.Class.getTypeParameters() definition code for java.lang.Class.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 sample code for java.lang.Class.isAnnotation() definition code for java.lang.Class.isAnnotation() ()
          Returns true if this Class object represents an annotation type.
 boolean isAnnotationPresent sample code for java.lang.Class.isAnnotationPresent(java.lang.Class) definition code for java.lang.Class.isAnnotationPresent(java.lang.Class) (Class sample code for java.lang.Class definition code for java.lang.Class <? extends Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation > annotationClass)
          Returns true if an annotation for the specified type is present on this element, else false.
 boolean isAnonymousClass sample code for java.lang.Class.isAnonymousClass() definition code for java.lang.Class.isAnonymousClass() ()
          Returns true if and only if the underlying class is an anonymous class.
 boolean isArray sample code for java.lang.Class.isArray() definition code for java.lang.Class.isArray() ()
          Determines if this Class object represents an array class.
 boolean isAssignableFrom sample code for java.lang.Class.isAssignableFrom(java.lang.Class) definition code for java.lang.Class.isAssignableFrom(java.lang.Class) (Class sample code for java.lang.Class definition code for java.lang.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 sample code for java.lang.Class.isEnum() definition code for java.lang.Class.isEnum() ()
          Returns true if and only if this class was declared as an enum in the source code.
 boolean isInstance sample code for java.lang.Class.isInstance(java.lang.Object) definition code for java.lang.Class.isInstance(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  obj)
          Determines if the specified Object is assignment-compatible with the object represented by this Class.
 boolean isInterface sample code for java.lang.Class.isInterface() definition code for java.lang.Class.isInterface() ()
          Determines if the specified Class object represents an interface type.
 boolean isLocalClass sample code for java.lang.Class.isLocalClass() definition code for java.lang.Class.isLocalClass() ()
          Returns true if and only if the underlying class is a local class.
 boolean isMemberClass sample code for java.lang.Class.isMemberClass() definition code for java.lang.Class.isMemberClass() ()
          Returns true if and only if the underlying class is a member class.
 boolean isPrimitive sample code for java.lang.Class.isPrimitive() definition code for java.lang.Class.isPrimitive() ()
          Determines if the specified Class object represents a primitive type.
 boolean isSynthetic sample code for java.lang.Class.isSynthetic() definition code for java.lang.Class.isSynthetic() ()
          Returns true if this class is a synthetic class; returns false otherwise.
 T newInstance sample code for java.lang.Class.newInstance() definition code for java.lang.Class.newInstance() ()
          Creates a new instance of the class represented by this Class object.
 String sample code for java.lang.String definition code for java.lang.String toString sample code for java.lang.Class.toString() definition code for java.lang.Class.toString() ()
          Converts the object to a string.
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Method Detail

toString sample code for java.lang.Class.toString() definition code for java.lang.Class.toString()

public String sample code for java.lang.String definition code for java.lang.String  toString()
Converts the object to a string. The string representation is the string "class" or "interface", followed by a space, and then by the fully qualified name of the class in the format returned by 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".

Overrides:
toString sample code for java.lang.Object.toString() definition code for java.lang.Object.toString() in class Object sample code for java.lang.Object definition code for java.lang.Object
Returns:
a string representation of this class object.

forName sample code for java.lang.Class.forName(java.lang.String) definition code for java.lang.Class.forName(java.lang.String)

public static Class sample code for java.lang.Class definition code for java.lang.Class <?> forName(String sample code for java.lang.String definition code for java.lang.String  className)
                        throws ClassNotFoundException sample code for java.lang.ClassNotFoundException definition code for java.lang.ClassNotFoundException 
Returns the Class 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.

Parameters:
className - the fully qualified name of the desired class.
Returns:
the Class object for the class with the specified name.
Throws:
LinkageError sample code for java.lang.LinkageError definition code for java.lang.LinkageError - if the linkage fails
ExceptionInInitializerError sample code for java.lang.ExceptionInInitializerError definition code for java.lang.ExceptionInInitializerError - if the initialization provoked by this method fails
ClassNotFoundException sample code for java.lang.ClassNotFoundException definition code for java.lang.ClassNotFoundException - if the class cannot be located

forName sample code for java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) definition code for java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader)

public static Class sample code for java.lang.Class definition code for java.lang.Class <?> forName(String sample code for java.lang.String definition code for java.lang.String  name,
                               boolean initialize,
                               ClassLoader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader  loader)
                        throws ClassNotFoundException sample code for java.lang.ClassNotFoundException definition code for java.lang.ClassNotFoundException 
Returns the Class 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, load, and link 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.

If the loader is null, and a security manager is present, and the caller's class loader is not null, then this method calls the security manager's checkPermission method with a RuntimePermission("getClassLoader") permission to ensure it's ok to access the bootstrap class loader.

Parameters:
name - fully qualified name of the desired class
initialize - whether the class must be initialized
loader - class loader from which the class must be loaded
Returns:
class object representing the desired class
Throws:
LinkageError sample code for java.lang.LinkageError definition code for java.lang.LinkageError - if the linkage fails
ExceptionInInitializerError sample code for java.lang.ExceptionInInitializerError definition code for java.lang.ExceptionInInitializerError - if the initialization provoked by this method fails
ClassNotFoundException sample code for java.lang.ClassNotFoundException definition code for java.lang.ClassNotFoundException - if the class cannot be located by the specified class loader
Since:
1.2
See Also:
forName(String) sample code for java.lang.Class.forName(java.lang.String) definition code for java.lang.Class.forName(java.lang.String) , ClassLoader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader

newInstance sample code for java.lang.Class.newInstance() definition code for java.lang.Class.newInstance()

public T newInstance()
              throws InstantiationException sample code for java.lang.InstantiationException definition code for java.lang.InstantiationException ,
                     IllegalAccessException sample code for java.lang.IllegalAccessException definition code for java.lang.IllegalAccessException 
Creates a new instance of the class represented by this 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.

Note that this method propagates any exception thrown by the nullary constructor, including a checked exception. Use of this method effectively bypasses the compile-time exception checking that would otherwise be performed by the compiler. The Constructor.newInstance sample code for java.lang.reflect.Constructor.newInstance(java.lang.Object...) definition code for java.lang.reflect.Constructor.newInstance(java.lang.Object...) method avoids this problem by wrapping any exception thrown by the constructor in a (checked) InvocationTargetException sample code for java.lang.reflect.InvocationTargetException definition code for java.lang.reflect.InvocationTargetException .

Returns:
a newly allocated instance of the class represented by this object.
Throws:
IllegalAccessException sample code for java.lang.IllegalAccessException definition code for java.lang.IllegalAccessException - if the class or its nullary constructor is not accessible.
InstantiationException sample code for java.lang.InstantiationException definition code for java.lang.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 sample code for java.lang.ExceptionInInitializerError definition code for java.lang.ExceptionInInitializerError - if the initialization provoked by this method fails.
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:

isInstance sample code for java.lang.Class.isInstance(java.lang.Object) definition code for java.lang.Class.isInstance(java.lang.Object)

public boolean isInstance(Object sample code for java.lang.Object definition code for java.lang.Object  obj)
Determines if the specified 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.

Parameters:
obj - the object to check
Returns:
true if obj is an instance of this class
Since:
JDK1.1

isAssignableFrom sample code for java.lang.Class.isAssignableFrom(java.lang.Class<?>) definition code for java.lang.Class.isAssignableFrom(java.lang.Class<?>)

public boolean isAssignableFrom(Class sample code for java.lang.Class definition code for java.lang.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. 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.

Parameters:
cls - the Class object to be checked
Returns:
the boolean value indicating whether objects of the type cls can be assigned to objects of this class
Throws:
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the specified Class parameter is null.
Since:
JDK1.1

isInterface sample code for java.lang.Class.isInterface() definition code for java.lang.Class.isInterface()

public boolean isInterface()
Determines if the specified Class object represents an interface type.

Returns:
true if this object represents an interface; false otherwise.

isArray sample code for java.lang.Class.isArray() definition code for java.lang.Class.isArray()

public boolean isArray()
Determines if this Class object represents an array class.

Returns:
true if this object represents an array class; false otherwise.
Since:
JDK1.1

isPrimitive sample code for java.lang.Class.isPrimitive() definition code for java.lang.Class.isPrimitive()

public boolean isPrimitive()
Determines if the specified 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.

Returns:
true if and only if this class represents a primitive type
Since:
JDK1.1
See Also:
Boolean.TYPE sample code for java.lang.Boolean.TYPE definition code for java.lang.Boolean.TYPE , Character.TYPE sample code for java.lang.Character.TYPE definition code for java.lang.Character.TYPE , Byte.TYPE sample code for java.lang.Byte.TYPE definition code for java.lang.Byte.TYPE , Short.TYPE sample code for java.lang.Short.TYPE definition code for java.lang.Short.TYPE , Integer.TYPE sample code for java.lang.Integer.TYPE definition code for java.lang.Integer.TYPE , Long.TYPE sample code for java.lang.Long.TYPE definition code for java.lang.Long.TYPE , Float.TYPE sample code for java.lang.Float.TYPE definition code for java.lang.Float.TYPE , Double.TYPE sample code for java.lang.Double.TYPE definition code for java.lang.Double.TYPE , Void.TYPE sample code for java.lang.Void.TYPE definition code for java.lang.Void.TYPE

isAnnotation sample code for java.lang.Class.isAnnotation() definition code for java.lang.Class.isAnnotation()

public boolean isAnnotation()
Returns true if this Class object represents an annotation type. Note that if this method returns true, isInterface() sample code for java.lang.Class.isInterface() definition code for java.lang.Class.isInterface() would also return true, as all annotation types are also interfaces.

Returns:
true if this class object represents an annotation type; false otherwise
Since:
1.5

isSynthetic sample code for java.lang.Class.isSynthetic() definition code for java.lang.Class.isSynthetic()

public boolean isSynthetic()
Returns true if this class is a synthetic class; returns false otherwise.

Returns:
true if and only if this class is a synthetic class as defined by the Java Language Specification.
Since:
1.5

getName sample code for java.lang.Class.getName() definition code for java.lang.Class.getName()

public String sample code for java.lang.String definition code for java.lang.String  getName()
Returns the name of the entity (class, interface, array class, primitive type, or void) represented by this Class object, as a String.

If this class object represents a reference type that is not an array type then the binary name of the class is returned, as specified by the Java Language Specification, Second Edition.

If this class object represents a primitive type or void, then the name returned is a String equal to the Java language keyword corresponding to the primitive type or void.

If this class object represents a class of arrays, then the internal form of the name consists of the name of the element type preceded by one or more '[' characters representing the depth of the array nesting. The encoding of element type names is as follows:

Element Type Encoding
boolean Z
byte B
char C
class or interface Lclassname;
double D
float F
int I
long J
short S

The class or interface name classname is the binary name of the class specified above.

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"
 

Returns:
the name of the class or interface represented by this object.

getClassLoader sample code for java.lang.Class.getClassLoader() definition code for java.lang.Class.getClassLoader()

public ClassLoader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader  getClassLoader()
Returns the class loader for the class. Some implementations may use null to represent the bootstrap class loader. This method will return null in such implementations if this class was loaded by the bootstrap class loader.

If a security manager is present, and the caller's class loader is not null and the caller's class loader is not the same as or an ancestor of the class loader for the class whose class loader is requested, then this method calls the security manager's checkPermission method with a RuntimePermission("getClassLoader") permission to ensure it's ok to access the class loader for the class.

If this object represents a primitive type or void, null is returned.

Returns:
the class loader that loaded the class or interface represented by this object.
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - if a security manager exists and its checkPermission method denies access to the class loader for the class.
See Also:
ClassLoader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader , SecurityManager.checkPermission(java.security.Permission) sample code for java.lang.SecurityManager.checkPermission(java.security.Permission) definition code for java.lang.SecurityManager.checkPermission(java.security.Permission) , RuntimePermission sample code for java.lang.RuntimePermission definition code for java.lang.RuntimePermission

getTypeParameters sample code for java.lang.Class.getTypeParameters() definition code for java.lang.Class.getTypeParameters()

public TypeVariable sample code for java.lang.reflect.TypeVariable definition code for java.lang.reflect.TypeVariable <Class sample code for java.lang.Class definition code for java.lang.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. Returns an array of length 0 if the underlying generic declaration declares no type variables.

Specified by:
getTypeParameters sample code for java.lang.reflect.GenericDeclaration.getTypeParameters() definition code for java.lang.reflect.GenericDeclaration.getTypeParameters() in interface GenericDeclaration sample code for java.lang.reflect.GenericDeclaration definition code for java.lang.reflect.GenericDeclaration
Returns:
an array of TypeVariable objects that represent the type variables declared by this generic declaration
Throws:
GenericSignatureFormatError - if the generic signature of this generic declaration does not conform to the format specified in the Java Virtual Machine Specification, 3rd edition
Since:
1.5

getSuperclass sample code for java.lang.Class.getSuperclass() definition code for java.lang.Class.getSuperclass()

public Class sample code for java.lang.Class definition code for java.lang.Class <? super T> getSuperclass()
Returns the Class representing the 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 object represents an array class then the Class object representing the Object class is returned.

Returns:
the superclass of the class represented by this object.

getGenericSuperclass sample code for java.lang.Class.getGenericSuperclass() definition code for java.lang.Class.getGenericSuperclass()

public Type sample code for java.lang.reflect.Type definition code for java.lang.reflect.Type  getGenericSuperclass()
Returns the Type representing the direct superclass of the entity (class, interface, primitive type or void) represented by this Class.

If the superclass is a parameterized type, the Type object returned must accurately reflect the actual type parameters 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 sample code for java.lang.reflect.ParameterizedType definition code for java.lang.reflect.ParameterizedType for the semantics of the creation process for parameterized types. If this Class represents either the Object class, an interface, a primitive type, or void, then null is returned. If this object represents an array class then the Class object representing the Object class is returned.

Returns:
the superclass of the class represented by this object
Throws:
GenericSignatureFormatError - if the generic class signature does not conform to the format specified in the Java Virtual Machine Specification, 3rd edition
TypeNotPresentException sample code for java.lang.TypeNotPresentException definition code for java.lang.TypeNotPresentException - if the generic superclass refers to a non-existent type declaration
MalformedParameterizedTypeException - if the generic superclass refers to a parameterized type that cannot be instantiated for any reason
Since:
1.5

getPackage sample code for java.lang.Class.getPackage() definition code for java.lang.Class.getPackage()

public Package sample code for java.lang.Package definition code for java.lang.Package  getPackage()
Gets the package for this class. The class loader of this class is used to find the package. If the class was loaded by the bootstrap class loader the set of packages loaded from CLASSPATH is searched to find the package of the class. Null is returned if no package object was created by the class loader of this class.

Packages have attributes for versions and specifications only if the information was defined in the manifests that accompany the classes, and if the class loader created the package instance with the attributes from the manifest.

Returns:
the package of the class, or null if no package information is available from the archive or codebase.

getInterfaces sample code for java.lang.Class.getInterfaces() definition code for java.lang.Class.getInterfaces()

public Class sample code for java.lang.Class definition code for java.lang.Class [] getInterfaces()
Determines the interfaces implemented by the class or interface represented by this object.

If this object represents a class, the return value is an array containing objects representing all interfaces 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 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 object represents an interface, the array contains objects representing all interfaces 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 object.

If this object represents a class or interface that implements no interfaces, the method returns an array of length 0.

If this object represents a primitive type or void, the method returns an array of length 0.

Returns:
an array of interfaces implemented by this class.

getGenericInterfaces sample code for java.lang.Class.getGenericInterfaces() definition code for java.lang.Class.getGenericInterfaces()

public Type sample code for java.lang.reflect.Type definition code for java.lang.reflect.Type [] getGenericInterfaces()
Returns the Types representing the interfaces directly implemented by the class or interface represented by this object.

If a superinterface is a parameterized type, the Type object returned for it must accurately reflect the actual type parameters 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 sample code for java.lang.reflect.ParameterizedType definition code for java.lang.reflect.ParameterizedType for the semantics of the creation process for parameterized types.

If this object represents a class, the return value is an array containing objects representing all interfaces 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 object. In the case of an array class, the interfaces Cloneable and Serializable are returned in that order.

If this 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 object.

If this object represents a class or interface that implements no interfaces, the method returns an array of length 0.

If this object represents a primitive type or void, the method returns an array of length 0.

Returns:
an array of interfaces implemented by this class
Throws:
GenericSignatureFormatError - if the generic class signature does not conform to the format specified in the Java Virtual Machine Specification, 3rd edition
TypeNotPresentException sample code for java.lang.TypeNotPresentException definition code for java.lang.TypeNotPresentException - if any of the generic superinterfaces refers to a non-existent type declaration
MalformedParameterizedTypeException - if any of the generic superinterfaces refer to a parameterized type that cannot be instantiated for any reason
Since:
1.5

getComponentType sample code for java.lang.Class.getComponentType() definition code for java.lang.Class.getComponentType()

public Class sample code for java.lang.Class definition code for java.lang.Class <?> getComponentType()
Returns the Class representing the component type of an array. If this class does not represent an array class this method returns null.

Returns:
the Class representing the component type of this class if this class is an array
Since:
JDK1.1
See Also:
Array sample code for java.lang.reflect.Array definition code for java.lang.reflect.Array

getModifiers sample code for java.lang.Class.getModifiers() definition code for java.lang.Class.getModifiers()

public int getModifiers()
Returns the Java language modifiers for this class or interface, encoded in an integer. The modifiers consist of the Java Virtual Machine's constants for public, 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 represents a primitive type or void, its public modifier is always true, and its protected and private modifiers are always false. If this 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 The Java Virtual Machine Specification, table 4.1.

Returns:
the int representing the modifiers for this class
Since:
JDK1.1
See Also:
Modifier sample code for java.lang.reflect.Modifier definition code for java.lang.reflect.Modifier

getSigners sample code for java.lang.Class.getSigners() definition code for java.lang.Class.getSigners()

public Object sample code for java.lang.Object definition code for java.lang.Object [] getSigners()
Gets the signers of this class.

Returns:
the signers of this class, or null if there are no signers. In particular, this method returns null if this object represents a primitive type or void.
Since:
JDK1.1

getEnclosingMethod sample code for java.lang.Class.getEnclosingMethod() definition code for java.lang.Class.getEnclosingMethod()

public Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method  getEnclosingMethod()
If this Class object represents a local or anonymous class within a method, returns a Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.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.

Returns:
the immediately enclosing method of the underlying class, if that class is a local or anonymous class; otherwise null.
Since:
1.5

getEnclosingConstructor sample code for java.lang.Class.getEnclosingConstructor() definition code for java.lang.Class.getEnclosingConstructor()

public Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor <?> getEnclosingConstructor()
If this Class object represents a local or anonymous class within a constructor, returns a Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.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.

Returns:
the immediately enclosing constructor of the underlying class, if that class is a local or anonymous class; otherwise null.
Since:
1.5

getDeclaringClass sample code for java.lang.Class.getDeclaringClass() definition code for java.lang.Class.getDeclaringClass()

public Class sample code for java.lang.Class definition code for java.lang.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. 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.

Returns:
the declaring class for this class
Since:
JDK1.1

getEnclosingClass sample code for java.lang.Class.getEnclosingClass() definition code for java.lang.Class.getEnclosingClass()

public Class sample code for java.lang.Class definition code for java.lang.Class <?> getEnclosingClass()
Returns the immediately enclosing class of the underlying class. If the underlying class is a top level class this method returns null.

Returns:
the immediately enclosing class of the underlying class
Since:
1.5

getSimpleName sample code for java.lang.Class.getSimpleName() definition code for java.lang.Class.getSimpleName()

public String sample code for java.lang.String definition code for java.lang.String  getSimpleName()
Returns the simple name of the underlying class as given in the source code. Returns an empty string if the underlying class is anonymous.

The 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 "[]".

Returns:
the simple name of the underlying class
Since:
1.5

getCanonicalName sample code for java.lang.Class.getCanonicalName() definition code for java.lang.Class.getCanonicalName()

public String sample code for java.lang.String definition code for java.lang.String  getCanonicalName()
Returns the canonical name of the the underlying class as defined by the Java Language Specification. Returns null if the underlying class does not have a canonical name (i.e., if it is a local or anonymous class or an array whose component type does not have a canonical name).

Returns:
the canonical name of the underlying class if it exists, and null otherwise.
Since:
1.5

isAnonymousClass sample code for java.lang.Class.isAnonymousClass() definition code for java.lang.Class.isAnonymousClass()

public boolean isAnonymousClass()
Returns true if and only if the underlying class is an anonymous class.

Returns:
true if and only if this class is an anonymous class.
Since:
1.5

isLocalClass sample code for java.lang.Class.isLocalClass() definition code for java.lang.Class.isLocalClass()

public boolean isLocalClass()
Returns true if and only if the underlying class is a local class.

Returns:
true if and only if this class is a local class.
Since:
1.5

isMemberClass sample code for java.lang.Class.isMemberClass() definition code for java.lang.Class.isMemberClass()

public boolean isMemberClass()
Returns true if and only if the underlying class is a member class.

Returns:
true if and only if this class is a member class.
Since:
1.5

getClasses sample code for java.lang.Class.getClasses() definition code for java.lang.Class.getClasses()

public Class sample code for java.lang.Class definition code for java.lang.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. 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.

Returns:
the array of Class objects representing the public members of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getFields sample code for java.lang.Class.getFields() definition code for java.lang.Class.getFields()

public Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field [] getFields()
                  throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns an array containing Field objects reflecting all the accessible public fields of the class or interface represented by this Class object. The elements in the array returned are not sorted and are not in any particular order. This method returns an array of length 0 if the class or interface has no accessible public fields, or if it represents an array class, a primitive type, or void.

Specifically, if this Class object represents a class, this method returns the public fields of this class and of all its superclasses. If this Class object represents an interface, this method returns the fields of this interface and of all its superinterfaces.

The implicit length field for array class is not reflected by this method. User code should use the methods of class Array to manipulate arrays.

See The Java Language Specification, sections 8.2 and 8.3.

Returns:
the array of Field objects representing the public fields
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getMethods sample code for java.lang.Class.getMethods() definition code for java.lang.Class.getMethods()

public Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method [] getMethods()
                    throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
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. Array classes return all the (public) member methods inherited from the Object class. The elements in the array returned are not sorted and are not in any particular order. This method returns an array of length 0 if this Class object represents a class or interface that has no public member methods, or if this Class object represents a primitive type or void.

The class initialization method <clinit> is not included in the returned array. If the class declares multiple public member methods with the same parameter types, they are all included in the returned array.

See The Java Language Specification, sections 8.2 and 8.4.

Returns:
the array of Method objects representing the public methods of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getConstructors sample code for java.lang.Class.getConstructors() definition code for java.lang.Class.getConstructors()

public Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor [] getConstructors()
                              throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns an array containing 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.

Returns:
the array containing Method objects for all the declared public constructors of this class matches the specified parameterTypes
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getField sample code for java.lang.Class.getField(java.lang.String) definition code for java.lang.Class.getField(java.lang.String)

public Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field  getField(String sample code for java.lang.String definition code for java.lang.String  name)
               throws NoSuchFieldException sample code for java.lang.NoSuchFieldException definition code for java.lang.NoSuchFieldException ,
                      SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns a 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 represented by this object:

  1. If C declares a public field with the name specified, that is the field to be reflected.
  2. If no field was found in step 1 above, this algorithm is applied recursively to each direct superinterface of C. The direct superinterfaces are searched in the order they were declared.
  3. If no field was found in steps 1 and 2 above, and C has a superclass S, then this algorithm is invoked recursively upon S. If C has no superclass, then a NoSuchFieldException is thrown.

See The Java Language Specification, sections 8.2 and 8.3.

Parameters:
name - the field name
Returns:
the Field object of this class specified by name
Throws:
NoSuchFieldException sample code for java.lang.NoSuchFieldException definition code for java.lang.NoSuchFieldException - if a field with the specified name is not found.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if name is null
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getMethod sample code for java.lang.Class.getMethod(java.lang.String, java.lang.Class...) definition code for java.lang.Class.getMethod(java.lang.String, java.lang.Class...)

public Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method  getMethod(String sample code for java.lang.String definition code for java.lang.String  name,
                        Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
                 throws NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException ,
                        SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns a 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 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 the name is "<init>"or "<clinit>" a NoSuchMethodException is raised. Otherwise, the method to be reflected is determined by the algorithm that follows. Let C be the class represented by this object:

  1. C is searched for any matching methods. If no matching method is found, the algorithm of step 1 is invoked recursively on the superclass of C.
  2. If no method was found in step 1 above, the superinterfaces of C are searched for a matching method. If any such method is found, it is reflected.
To find a matching method in a class C:  If C declares exactly one public method with the specified name and exactly the same formal parameter types, that is the method reflected. If more than one such method is found in C, and one of these methods has a return type that is more specific than any of the others, that method is reflected; otherwise one of the methods is chosen arbitrarily.

See The Java Language Specification, sections 8.2 and 8.4.

Parameters:
name - the name of the method
parameterTypes - the list of parameters
Returns:
the Method object that matches the specified name and parameterTypes
Throws:
NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException - if a matching method is not found or if the name is "<init>"or "<clinit>".
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if name is null
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getConstructor sample code for java.lang.Class.getConstructor(java.lang.Class...) definition code for java.lang.Class.getConstructor(java.lang.Class...)

public Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor <T> getConstructor(Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
                              throws NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException ,
                                     SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns a 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.

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.

Parameters:
parameterTypes - the parameter array
Returns:
the Method object of the public constructor that matches the specified parameterTypes
Throws:
NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException - if a matching method is not found.
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredClasses sample code for java.lang.Class.getDeclaredClasses() definition code for java.lang.Class.getDeclaredClasses()

public Class sample code for java.lang.Class definition code for java.lang.Class [] getDeclaredClasses()
                           throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns an array of 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.

Returns:
the array of Class objects representing all the declared members of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredFields sample code for java.lang.Class.getDeclaredFields() definition code for java.lang.Class.getDeclaredFields()

public Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field [] getDeclaredFields()
                          throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns an array of 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. The elements in the array returned are not sorted and are not in any particular order. This method returns an array of length 0 if the class or interface declares no fields, or if this Class object represents a primitive type, an array class, or void.

See The Java Language Specification, sections 8.2 and 8.3.

Returns:
the array of Field objects representing all the declared fields of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredMethods sample code for java.lang.Class.getDeclaredMethods() definition code for java.lang.Class.getDeclaredMethods()

public Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method [] getDeclaredMethods()
                            throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns an array of Method objects reflecting all the methods declared by the class or interface represented by this Class object. This includes public, protected, default (package) access, and private methods, but excludes inherited methods. The elements in the array returned are not sorted and are not in any particular order. This method returns an array of length 0 if the class or interface declares no methods, or if this Class object represents a primitive type, an array class, or void. The class initialization method <clinit> is not included in the returned array. If the class declares multiple public member methods with the same parameter types, they are all included in the returned array.

See The Java Language Specification, section 8.2.

Returns:
the array of Method objects representing all the declared methods of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredConstructors sample code for java.lang.Class.getDeclaredConstructors() definition code for java.lang.Class.getDeclaredConstructors()

public Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor [] getDeclaredConstructors()
                                      throws SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns an array of 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.

Returns:
the array of Method objects representing all the declared constructors of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredField sample code for java.lang.Class.getDeclaredField(java.lang.String) definition code for java.lang.Class.getDeclaredField(java.lang.String)

public Field sample code for java.lang.reflect.Field definition code for java.lang.reflect.Field  getDeclaredField(String sample code for java.lang.String definition code for java.lang.String  name)
                       throws NoSuchFieldException sample code for java.lang.NoSuchFieldException definition code for java.lang.NoSuchFieldException ,
                              SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns a 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. Note that this method will not reflect the length field of an array class.

Parameters:
name - the name of the field
Returns:
the Field object for the specified field in this class
Throws:
NoSuchFieldException sample code for java.lang.NoSuchFieldException definition code for java.lang.NoSuchFieldException - if a field with the specified name is not found.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if name is null
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredMethod sample code for java.lang.Class.getDeclaredMethod(java.lang.String, java.lang.Class...) definition code for java.lang.Class.getDeclaredMethod(java.lang.String, java.lang.Class...)

public Method sample code for java.lang.reflect.Method definition code for java.lang.reflect.Method  getDeclaredMethod(String sample code for java.lang.String definition code for java.lang.String  name,
                                Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
                         throws NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException ,
                                SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns a 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.

Parameters:
name - the name of the method
parameterTypes - the parameter array
Returns:
the Method object for the method of this class matching the specified name and parameters
Throws:
NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException - if a matching method is not found.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if name is null
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getDeclaredConstructor sample code for java.lang.Class.getDeclaredConstructor(java.lang.Class...) definition code for java.lang.Class.getDeclaredConstructor(java.lang.Class...)

public Constructor sample code for java.lang.reflect.Constructor definition code for java.lang.reflect.Constructor <T> getDeclaredConstructor(Class sample code for java.lang.Class definition code for java.lang.Class ... parameterTypes)
                                      throws NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException ,
                                             SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException 
Returns a 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.

Parameters:
parameterTypes - the parameter array
Returns:
The Method object for the constructor with the specified parameter list
Throws:
NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException - if a matching method is not found.
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager, s, is present and any of the following conditions is met:
Since:
JDK1.1

getResourceAsStream sample code for java.lang.Class.getResourceAsStream(java.lang.String) definition code for java.lang.Class.getResourceAsStream(java.lang.String)

public InputStream sample code for java.io.InputStream definition code for java.io.InputStream  getResourceAsStream(String sample code for java.lang.String definition code for java.lang.String  name)
Finds a resource with a given name. The rules for searching resources associated with a given class are implemented by the defining class loader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader of the class. This method delegates to this object's class loader. If this object was loaded by the bootstrap class loader, the method delegates to ClassLoader.getSystemResourceAsStream(java.lang.String) sample code for java.lang.ClassLoader.getSystemResourceAsStream(java.lang.String) definition code for java.lang.ClassLoader.getSystemResourceAsStream(java.lang.String) .

Before delegation, an absolute resource name is constructed from the given resource name using this algorithm:

Parameters:
name - name of the desired resource
Returns:
A InputStream sample code for java.io.InputStream definition code for java.io.InputStream object or null if no resource with this name is found
Throws:
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - If name is null
Since:
JDK1.1

getResource sample code for java.lang.Class.getResource(java.lang.String) definition code for java.lang.Class.getResource(java.lang.String)

public URL sample code for java.net.URL definition code for java.net.URL  getResource(String sample code for java.lang.String definition code for java.lang.String  name)
Finds a resource with a given name. The rules for searching resources associated with a given class are implemented by the defining class loader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader of the class. This method delegates to this object's class loader. If this object was loaded by the bootstrap class loader, the method delegates to ClassLoader.getSystemResource(java.lang.String) sample code for java.lang.ClassLoader.getSystemResource(java.lang.String) definition code for java.lang.ClassLoader.getSystemResource(java.lang.String) .

Before delegation, an absolute resource name is constructed from the given resource name using this algorithm:

Parameters:
name - name of the desired resource
Returns:
A URL sample code for java.net.URL definition code for java.net.URL object or null if no resource with this name is found
Since:
JDK1.1

getProtectionDomain sample code for java.lang.Class.getProtectionDomain() definition code for java.lang.Class.getProtectionDomain()

public ProtectionDomain sample code for java.security.ProtectionDomain definition code for java.security.ProtectionDomain  getProtectionDomain()
Returns the ProtectionDomain 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.

Returns:
the ProtectionDomain of this class
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - if a security manager exists and its checkPermission method doesn't allow getting the ProtectionDomain.
Since:
1.2
See Also:
ProtectionDomain sample code for java.security.ProtectionDomain definition code for java.security.ProtectionDomain , SecurityManager.checkPermission(java.security.Permission) sample code for java.lang.SecurityManager.checkPermission(java.security.Permission) definition code for java.lang.SecurityManager.checkPermission(java.security.Permission) , RuntimePermission sample code for java.lang.RuntimePermission definition code for java.lang.RuntimePermission

desiredAssertionStatus sample code for java.lang.Class.desiredAssertionStatus() definition code for java.lang.Class.desiredAssertionStatus()

public 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. If this class has had its assertion status set, the most recent setting will be returned; otherwise, if any package default assertion status pertains to this class, the most recent setting for the most specific pertinent package default assertion status is returned; otherwise, if this class is not a system class (i.e., it has a class loader) its class loader's default assertion status is returned; otherwise, the system class default assertion status is returned.

Few programmers will have any need for this method; it is provided for the benefit of the JRE itself. (It allows a class to determine at the time that it is initialized whether assertions should be enabled.) Note that this method is not guaranteed to return the actual assertion status that was (or will be) associated with the specified class when it was (or will be) initialized.

Returns:
the desired assertion status of the specified class.
Since:
1.4
See Also:
ClassLoader.setClassAssertionStatus(java.lang.String, boolean) sample code for java.lang.ClassLoader.setClassAssertionStatus(java.lang.String, boolean) definition code for java.lang.ClassLoader.setClassAssertionStatus(java.lang.String, boolean) , ClassLoader.setPackageAssertionStatus(java.lang.String, boolean) sample code for java.lang.ClassLoader.setPackageAssertionStatus(java.lang.String, boolean) definition code for java.lang.ClassLoader.setPackageAssertionStatus(java.lang.String, boolean) , ClassLoader.setDefaultAssertionStatus(boolean) sample code for java.lang.ClassLoader.setDefaultAssertionStatus(boolean) definition code for java.lang.ClassLoader.setDefaultAssertionStatus(boolean)

isEnum sample code for java.lang.Class.isEnum() definition code for java.lang.Class.isEnum()

public boolean isEnum()
Returns true if and only if this class was declared as an enum in the source code.

Returns:
true if and only if this class was declared as an enum in the source code
Since:
1.5

getEnumConstants sample code for java.lang.Class.getEnumConstants() definition code for java.lang.Class.getEnumConstants()

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

Returns:
an array containing the values comprising the enum class represented by this Class object in the order they're declared, or null if this Class object does not represent an enum type
Since:
1.5

cast sample code for java.lang.Class.cast(java.lang.Object) definition code for java.lang.Class.cast(java.lang.Object)

public T cast(Object sample code for java.lang.Object definition code for java.lang.Object  obj)
Casts an object to the class or interface represented by this Class object.

Parameters:
obj - the object to be cast
Returns:
the object after casting, or null if obj is null
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if the object is not null and is not assignable to the type T.
Since:
1.5

asSubclass sample code for java.lang.Class.<U>asSubclass(java.lang.Class<U>) definition code for java.lang.Class.<U>asSubclass(java.lang.Class<U>)

public <U> Class sample code for java.lang.Class definition code for java.lang.Class <? extends U> asSubclass(Class sample code for java.lang.Class definition code for java.lang.Class <U> clazz)
Casts this Class object to represent a subclass of the class represented by the specified class object. Checks that 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).

Returns:
this Class object, cast to represent a subclass of the specified class object.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if this Class object does not represent a subclass of the specified class (here "subclass" includes the class itself).
Since:
1.5

getAnnotation sample code for java.lang.Class.<A extends java.lang.annotation.Annotation>getAnnotation(java.lang.Class<A>) definition code for java.lang.Class.<A extends java.lang.annotation.Annotation>getAnnotation(java.lang.Class<A>)

public <A extends Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation > A getAnnotation(Class sample code for java.lang.Class definition code for java.lang.Class <A> annotationClass)
Returns this element's annotation for the specified type if such an annotation is present, else null.

Specified by:
getAnnotation sample code for java.lang.reflect.AnnotatedElement.getAnnotation(java.lang.Class) definition code for java.lang.reflect.AnnotatedElement.getAnnotation(java.lang.Class) in interface AnnotatedElement sample code for java.lang.reflect.AnnotatedElement definition code for java.lang.reflect.AnnotatedElement
Parameters:
annotationClass - the Class object corresponding to the annotation type
Returns:
this element's annotation for the specified annotation type if present on this element, else null

isAnnotationPresent sample code for java.lang.Class.isAnnotationPresent(java.lang.Class<? extends java.lang.annotation.Annotation>) definition code for java.lang.Class.isAnnotationPresent(java.lang.Class<? extends java.lang.annotation.Annotation>)

public boolean isAnnotationPresent(Class sample code for java.lang.Class definition code for java.lang.Class <? extends Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation > annotationClass)
Returns true if an annotation for the specified type is present on this element, else false. This method is designed primarily for convenient access to marker annotations.

Specified by:
isAnnotationPresent sample code for java.lang.reflect.AnnotatedElement.isAnnotationPresent(java.lang.Class) definition code for java.lang.reflect.AnnotatedElement.isAnnotationPresent(java.lang.Class) in interface AnnotatedElement sample code for java.lang.reflect.AnnotatedElement definition code for java.lang.reflect.AnnotatedElement
Parameters:
annotationClass - the Class object corresponding to the annotation type
Returns:
true if an annotation for the specified annotation type is present on this element, else false

getAnnotations sample code for java.lang.Class.getAnnotations() definition code for java.lang.Class.getAnnotations()

public Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation [] getAnnotations()
Returns all annotations present on this element. (Returns an array of length zero if this element has no annotations.) The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.

Specified by:
getAnnotations sample code for java.lang.reflect.AnnotatedElement.getAnnotations() definition code for java.lang.reflect.AnnotatedElement.getAnnotations() in interface AnnotatedElement sample code for java.lang.reflect.AnnotatedElement definition code for java.lang.reflect.AnnotatedElement
Returns:
all annotations present on this element

getDeclaredAnnotations sample code for java.lang.Class.getDeclaredAnnotations() definition code for java.lang.Class.getDeclaredAnnotations()

public Annotation sample code for java.lang.annotation.Annotation definition code for java.lang.annotation.Annotation [] getDeclaredAnnotations()
Returns all annotations that are directly present on this element. Unlike the other methods in this interface, this method ignores inherited annotations. (Returns an array of length zero if no annotations are directly present on this element.) The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.

Specified by:
getDeclaredAnnotations sample code for java.lang.reflect.AnnotatedElement.getDeclaredAnnotations() definition code for java.lang.reflect.AnnotatedElement.getDeclaredAnnotations() in interface AnnotatedElement sample code for java.lang.reflect.AnnotatedElement definition code for java.lang.reflect.AnnotatedElement
Returns:
All annotations directly present on this element