Name
CallbackHandler
Synopsis
A
CallbackHandler
is responsible for communication between the end-user of an
application and the
javax.security.auth.spi.LoginModule that is
performing authentication of that user on behalf of the
javax.security.auth.login.LoginContext
instantiated by the application. When an application needs to
authenticate a user, it creates a LoginContext and
specifies a CallbackHandler object for that
context. The underlying LoginModule uses the
CallbackHandler to communicate with the end
user—for example prompting them to enter a name and password.
The LoginModule passes an array of objects that
implement the Callback interface to the
handle( )
method of
CallbackHandler. The handle( )
method must determine the type of Callback object,
and display the information and/or prompt for the input it
represents. Different Callback classes have
different purposes and must be handled differently.
NameCallback and
PasswordCallback are two of the most commonly
used: they represent requests for the user’s name
and password. TextOutputCallback is also common:
it represents a request to display a message (such as
“Authentication Failed”) to the
user. See the descriptions of the individual
Callback classes for information on how a
CallbackHandler should handle them.
CallbackHandler implementations are not required
to support every type of Callback and my throw an
UnsupportedCallbackException if passed a
Callback object of a type they do not recognize or
do not support.
The handle( ...
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