com.xdev.security.authentication

Class SequenceAuthenticator<C,R>

java.lang.Object

com.xdev.security.authentication.SequenceAuthenticator<C,R>

Type Parameters:

C - the type of the credentials instance to be authenticated.

R - the type of the result/response instance to be returned upon an authentication attempt.

All Implemented Interfaces:

Authenticator<C,R>

public final class SequenceAuthenticator<C,R>
extends Object
implements Authenticator<C,R>

An implementation of Authenticator that wraps a sequence of passed authenticators in a new instance. For the exact behaviour, see authenticate(Object).

Author:

XDEV Software (TM)

Method Summary

Modifier and Type	Method and Description
R	authenticate(C credentials) Calling this method internally delegates to the same method of the passed authenticators in the exact same order as they have been passed at construction time.
Authenticator<? super C,R>[]	getAuthenticators() Returns a defensive copy of the internally used authenticator sequence.
static <C,R> SequenceAuthenticator<C,R>	New(Authenticator<? super C,R>... authenticators) Constructor method that does validation and implementation detail encapsulation of the actual constructor.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.xdev.security.authentication.Authenticator

lambda, sequence, then

Method Detail

New

@SafeVarargs
public static final <C,R> SequenceAuthenticator<C,R> New(Authenticator<? super C,R>... authenticators)
                                                                throws IllegalArgumentException

Constructor method that does validation and implementation detail encapsulation of the actual constructor.

The passed array of Authenticator instances may neither be null nor empty. The created instance uses a copy of the passed array internally to avoid any later side effects.

Parameters:

authenticators - the authenticators to be evaluated in order.

Returns:

a new authenticator instance wrapping a sequence of other Authenticator instances.

Throws:

IllegalArgumentException - if the passed array is empty.

See Also:

authenticate(Object)

getAuthenticators

public final Authenticator<? super C,R>[] getAuthenticators()

Returns a defensive copy of the internally used authenticator sequence.

Returns:

the wrapped authenticators.

authenticate

public final R authenticate(C credentials)
                     throws AuthenticationFailedException

Calling this method internally delegates to the same method of the passed authenticators in the exact same order as they have been passed at construction time. If an internally called authenticator produces one of the following results, the delegated authentication attempt is deemed a failure and the next authenticator in the sequence is used:

• returned value of null.
• returned value equal to Boolean.FALSE.
• an AuthenticationFailedException occured.

If the last authenticator is reached, it is called directly without any wrapping logic, returning any value and passing any exception it might throw.

This effectively creates a multi-attempt Authenticator that succeed on the first success of one of its subsidiary authenticators.

Specified by:

authenticate in interface Authenticator<C,R>

Parameters:

credentials - the credentials to be evaluated for the authentication.

Returns:

the first return value not deemed to indicate a failure or whatever the last authenticator returns.

Throws:

AuthenticationFailedException - if the last authenticator throws an AuthenticationFailedException.