# Package javax.security.auth.callback

This package provides the classes necessary for services to interact with applications in order to retrieve information (authentication data including usernames or passwords, for example) or to display information (error and warning messages, for example).

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  Callback | Implementations of this interface are passed to a `CallbackHandler`, allowing underlying security services the ability to interact with a calling application to retrieve specific authentication data such as usernames and passwords, or to display certain information, such as error and warning messages.
  CallbackHandler | An application implements a `CallbackHandler` and passes it to underlying security services so that they may interact with the application to retrieve specific authentication data, such as usernames and passwords, or to display certain information, such as error and warning messages.

- Class Summary
  Class | Description
  --- | ---
  ChoiceCallback | Underlying security services instantiate and pass a `ChoiceCallback` to the `handle` method of a `CallbackHandler` to display a list of choices and to retrieve the selected choice(s).
  ConfirmationCallback | Underlying security services instantiate and pass a `ConfirmationCallback` to the `handle` method of a `CallbackHandler` to ask for YES/NO, OK/CANCEL, YES/NO/CANCEL or other similar confirmations.
  LanguageCallback | Underlying security services instantiate and pass a `LanguageCallback` to the `handle` method of a `CallbackHandler` to retrieve the `Locale` used for localizing text.
  NameCallback | Underlying security services instantiate and pass a `NameCallback` to the `handle` method of a `CallbackHandler` to retrieve name information.
  PasswordCallback | Underlying security services instantiate and pass a `PasswordCallback` to the `handle` method of a `CallbackHandler` to retrieve password information.
  TextInputCallback | Underlying security services instantiate and pass a `TextInputCallback` to the `handle` method of a `CallbackHandler` to retrieve generic text information.
  TextOutputCallback | Underlying security services instantiate and pass a `TextOutputCallback` to the `handle` method of a `CallbackHandler` to display information messages, warning messages and error messages.

- Exception Summary
  Exception | Description
  --- | ---
  UnsupportedCallbackException | Signals that a `CallbackHandler` does not recognize a particular `Callback`.

## Package javax.security.auth.callback Description

This package provides the classes necessary for services to interact with applications in order to retrieve information (authentication data including usernames or passwords, for example) or to display information (error and warning messages, for example).

Since:
  JDK1.4

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