com.xdev.security.authentication

Interface Authenticator<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 Known Subinterfaces:

XdevInMemorySecurityManager, XdevSecurityManager<C,R>

All Known Implementing Classes:

ChainingAuthenticator, DBAuthenticator, InMemoryAuthenticator, JPAAuthenticator, LDAPAuthenticator, SequenceAuthenticator, XdevInMemorySecurityManager.Implementation, XdevSecurityManager.Implementation

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Authenticator<C,R>

Generic authenticator type. The concrete usage depends on how the type parameters are chosen for a specific requirement.

Type parameter C (credentials) can for example be CredentialsUsernamePassword. It could also be a specific type of a user or subject in order to authenticate already existing user instances.

Type parameter R (result) can be a Boolean for a simple information, if the authentication succeeded or failed. It can also be a concrete user instance in case a successful authentication has to create the user instance itself.

Author:

XDEV Software (TM)

Method Summary

Modifier and Type	Method and Description
R	authenticate(C credentials) Tries to authenticate the passed credentials and returns an apropriate result.
static <C,R> Authenticator<C,R>	lambda(Authenticator<C,R> lambda) Trivial helper method to compensate for the Java 8 lambda extension loophole that a lambda expression cannot be recognized without a target (variable declaration or method call). Example: Authenticator <C,R> chained = ((c,r) -> debugAuth(c)).then((c,r) -> authenticate(c)); With this trivial helper method, this is possible: Authenticator <C,R> chained = lambda((c,r) -> debugAuth(c)).then((c,r) -> authenticate(c));
static <C,R> Authenticator<C,R>	sequence(Authenticator<? super C,R>... authenticators) Returns a new Authenticator instance that wraps a sequence of passed authenticators.
default Authenticator<C,R>	then(Authenticator<C,R> other) Chains the passed Authenticator instance to this one to be evaluated in case the evaluation of this one returns a negative result.

Method Detail

authenticate

R authenticate(C credentials)
        throws AuthenticationFailedException

Tries to authenticate the passed credentials and returns an apropriate result. The exact meaning of the result is implementation-dependant.

Parameters:

credentials - the credentials to be authenticated

Returns:

the result of the authentication

Throws:

AuthenticationFailedException

then

default Authenticator<C,R> then(Authenticator<C,R> other)

Chains the passed Authenticator instance to this one to be evaluated in case the evaluation of this one returns a negative result.

Note that multiple authenticators can be chained in sequence

Parameters:

other - the authenticator instance to be chained.

Returns:

an authenticator instance that firstly attempts to evaluate this authenticator and then the passed one if necessary.

lambda

static <C,R> Authenticator<C,R> lambda(Authenticator<C,R> lambda)

Trivial helper method to compensate for the Java 8 lambda extension loophole that a lambda expression cannot be recognized without a target (variable declaration or method call).
Example:
Authenticator <C,R> chained = ((c,r) -> debugAuth(c)).then((c,r) -> authenticate(c));
With this trivial helper method, this is possible: Authenticator <C,R> chained = lambda((c,r) -> debugAuth(c)).then((c,r) -> authenticate(c));

Trivially always returns the passed instance (return lambda;.

Note that trivial static methods like this get eliminated (inlined) by the JIT compiler at runtime, so this convenience method does NOT come with a performance penalty.

Parameters:

lambda - the lambda instance to make recognizable to the compiler.

Returns:

lambda

sequence

@SafeVarargs
static <C,R> Authenticator<C,R> sequence(Authenticator<? super C,R>... authenticators)

Returns a new Authenticator instance that wraps a sequence of passed authenticators. For further details, see SequenceAuthenticator.

Parameters:

authenticators - the Authenticator instances sequence to be wrapped.

Returns:

a wrapping SequenceAuthenticator instance.