java.lang.reflect (Java Platform SE 8 )
Keywords: java.lang.reflect package
Date: 2026-06-25

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# Package java.lang.reflect

Provides classes and interfaces for obtaining reflective information about classes and objects.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  AnnotatedArrayType | `AnnotatedArrayType` represents the potentially annotated use of an array type, whose component type may itself represent the annotated use of a type.
  AnnotatedElement | Represents an annotated element of the program currently running in this VM.
  AnnotatedParameterizedType | `AnnotatedParameterizedType` represents the potentially annotated use of a parameterized type, whose type arguments may themselves represent annotated uses of types.
  AnnotatedType | `AnnotatedType` represents the potentially annotated use of a type in the program currently running in this VM.
  AnnotatedTypeVariable | `AnnotatedTypeVariable` represents the potentially annotated use of a type variable, whose declaration may have bounds which themselves represent annotated uses of types.
  AnnotatedWildcardType | `AnnotatedWildcardType` represents the potentially annotated use of a wildcard type argument, whose upper or lower bounds may themselves represent annotated uses of types.
  GenericArrayType | `GenericArrayType` represents an array type whose component type is either a parameterized type or a type variable.
  GenericDeclaration | A common interface for all entities that declare type variables.
  InvocationHandler | `InvocationHandler` is the interface implemented by the invocation handler of a proxy instance.
  Member | Member is an interface that reflects identifying information about a single member (a field or a method) or a constructor.
  ParameterizedType | ParameterizedType represents a parameterized type such as Collection<String>.
  Type | Type is the common superinterface for all types in the Java programming language.
  TypeVariable<D extends GenericDeclaration> | TypeVariable is the common superinterface for type variables of kinds.
  WildcardType | WildcardType represents a wildcard type expression, such as `?`, `? extends Number`, or `? super Integer`.

- Class Summary
  Class | Description
  --- | ---
  AccessibleObject | The AccessibleObject class is the base class for Field, Method and Constructor objects.
  Array | The `Array` class provides static methods to dynamically create and access Java arrays.
  Constructor<T> | `Constructor` provides information about, and access to, a single constructor for a class.
  Executable | A shared superclass for the common functionality of `Method` and `Constructor`.
  Field | A `Field` provides information about, and dynamic access to, a single field of a class or an interface.
  Method | A `Method` provides information about, and access to, a single method on a class or interface.
  Modifier | The Modifier class provides `static` methods and constants to decode class and member access modifiers.
  Parameter | Information about method parameters.
  Proxy | `Proxy` provides static methods for creating dynamic proxy classes and instances, and it is also the superclass of all dynamic proxy classes created by those methods.
  ReflectPermission | The Permission class for reflective operations.

- Exception Summary
  Exception | Description
  --- | ---
  InvocationTargetException | InvocationTargetException is a checked exception that wraps an exception thrown by an invoked method or constructor.
  MalformedParameterizedTypeException | Thrown when a semantically malformed parameterized type is encountered by a reflective method that needs to instantiate it.
  MalformedParametersException | Thrown when `the java.lang.reflect package` attempts to read method parameters from a class file and determines that one or more parameters are malformed.
  UndeclaredThrowableException | Thrown by a method invocation on a proxy instance if its invocation handler's `invoke` method throws a checked exception (a `Throwable` that is not assignable to `RuntimeException` or `Error`) that is not assignable to any of the exception types declared in the `throws` clause of the method that was invoked on the proxy instance and dispatched to the invocation handler.

- Error Summary
  Error | Description
  --- | ---
  GenericSignatureFormatError | Thrown when a syntactically malformed signature attribute is encountered by a reflective method that needs to interpret the generic signature information for a type, method or constructor.

## Package java.lang.reflect Description

Provides classes and interfaces for obtaining reflective information about classes and objects. Reflection allows programmatic access to information about the fields, methods and constructors of loaded classes, and the use of reflected fields, methods, and constructors to operate on their underlying counterparts, within security restrictions.

`AccessibleObject` allows suppression of access checks if the necessary `ReflectPermission` is available.

`Array` provides static methods to dynamically create and access arrays.

Classes in this package, along with `java.lang.Class` accommodate applications such as debuggers, interpreters, object inspectors, class browsers, and services such as Object Serialization and JavaBeans that need access to either the public members of a target object (based on its runtime class) or the members declared by a given class.

Since:
  JDK1.1

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