java reflection instantiate class by name

Reference type represented by this Class object without Object argument is non-null and can be cast to the The dynamic equivalent of the Java language instanceof With the object represented by this Class. isInstance public boolean isInstance( Object obj)ĭetermines if the specified Object is assignment-compatible.

Invocation of s.checkPackageAccess() denies access to the package the caller's class loader is not the same as or anĪncestor of the class loader for the current class and.S.checkMemberAccess(this, Member.PUBLIC) denies SecurityException - If a security manager, s, is present and any of the ExceptionInInitializerError - if the initialization Or if the instantiation fails for some other reason. Or if the class has no nullary constructor InstantiationException - if this Class represents an abstract class,Īn interface, an array class, a primitive type, or void Throws: IllegalAccessException - if the class or its nullaryĬonstructor is not accessible. Returns: a newly allocated instance of the class represented by this The Constructor.newInstance method avoids this problem by wrappingĪny exception thrown by the constructor in a (checked) InvocationTargetException. This method effectively bypasses the compile-time exceptionĬhecking that would otherwise be performed by the compiler. Nullary constructor, including a checked exception. Note that this method propagates any exception thrown by the The class is instantiated as if by a newĮxpression with an empty argument list. The specified class loader Since: 1.2 See Also: forName(String),Ĭreates a new instance of the class represented by this Class 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 - if the linkage fails ExceptionInInitializerError - if the initialization provokedīy this method fails ClassNotFoundException - if the class cannot be located by With a RuntimePermission('getClassLoader') permission toĮnsure it's ok to access the bootstrap class loader. Method calls the security manager's checkPermission method Manager is present, and the caller's class loader is not null, then this Note that this method does not check whether the requested class Initializing as specified in Sections 12.2, 12.3 and 12.4 of The Note that this method throws errors related to loading, linking or The array class is loaded but not initialized.įor example, in an instance method the expression:Ĭlass.forName('Foo', true, this.getClass().getClassLoader()) If name denotes an array class, the component type of Obtain any of the Class objects representing primitive Will be made to locate a user-defined class in the unnamed package whose If name denotes a primitive type or void, an attempt Initialize parameter is true and if it has Loader is null, the class is loaded through the bootstrapĬlass loader. Loader is used to load the class or interface. Locate, load, and link the class or interface. Given the fully qualified name for a class or interface (in the sameįormat returned by getName) this method attempts to Interface with the given string name, using the given class loader. Returns the Class object associated with the class or ('The name of class Foo is: '+()) Since: JDK1.0 See Also: fineClass(byte, int, int), Type (or for void) using a class literal. It is also possible to get the Class object for a named The following example uses a Class object to print the Objects are constructed automatically by the Java Virtual Machine as classesĪre loaded and by calls to the defineClass method in the class The primitive Java types ( boolean,Ĭlass has no public constructor. That is shared by all arrays with the same element type and number Every array alsoīelongs to a class that is reflected as a Class object An enum is a kind ofĬlass and an annotation is a kind of interface. Interfaces in a running Java application. Instances of the class Class represent classes and

Java reflection instantiate class by name