Package net.shibboleth.shared.logic

Class FunctionSupport

java.lang.Object
net.shibboleth.shared.logic.FunctionSupport
public final class FunctionSupport extends Object
Helper class for constructing functions that are fully generic, in contrast to the broken, Object-bound types Guava can build.

  • Constructor Details

    • FunctionSupport

      private FunctionSupport()
      Constructor.

  • Method Details

    • constant

      @Nonnull public static <T1, T2> Function<T1,T2> constant(@Nullable @ParameterName(name="target") T2 target)
      Creates a function that returns a constant value.
      Type Parameters:
      T1 - type of object the function needs to act on
      T2 - type of object being returned
      Parameters:
      target - the value to return from the function
      Returns:
      the constructed function

    • compose

      @Nonnull public static <A, B, C> Function<A,C> compose(@Nonnull @ParameterName(name="g") Function<? super B,? extends C> g, @Nonnull @ParameterName(name="f") Function<A,? extends B> f)
      Returns the composition of two functions. For f: A->B and g: B->C, composition is defined as the function h such that h(a) == g(f(a)) for each a.
      Type Parameters:
      A - input to composed function
      B - output of inner function
      C - output of composed function
      Parameters:
      g - the second function to apply
      f - the first function to apply
      Returns:
      the composition of f and g
      See Also:

    • forPredicate

      @Nonnull public static <T> Function<T,Boolean> forPredicate(@Nonnull @ParameterName(name="predicate") Predicate<T> predicate)
      Creates a function that returns the same boolean output as the given predicate for all inputs.

      Primarily provided for Spring wiring use cases that can't express a method reference.

      Type Parameters:
      T - input type
      Parameters:
      predicate - input predicate
      Returns:
      a corresponding function