java.util.function

Interface Predicate<T>

  • Type Parameters:
    T - the type of the input to the predicate
    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 Predicate<T>
    Represents a predicate (boolean-valued function) of one argument.

    This is a functional interface whose functional method is test(Object).

    Since:
    1.8

    • Method Summary

      Modifier and Type Method and Description
      default Predicate<T> and(Predicate<? super T> other)
      Returns a composed predicate that represents a short-circuiting logical AND of this predicate and another.
      static <T> Predicate<T> isEqual(Object targetRef)
      Returns a predicate that tests if two arguments are equal according to Objects.equals(Object, Object).
      default Predicate<T> negate()
      Returns a predicate that represents the logical negation of this predicate.
      default Predicate<T> or(Predicate<? super T> other)
      Returns a composed predicate that represents a short-circuiting logical OR of this predicate and another.
      boolean test(T t)
      Evaluates this predicate on the given argument.

    • Method Detail

      • test

        boolean test(T t)
        Evaluates this predicate on the given argument.
        Parameters:
        t - the input argument
        Returns:
        true if the input argument matches the predicate, otherwise false

      • and

        default Predicate<T> and(Predicate<? super T> other)
        Returns a composed predicate that represents a short-circuiting logical AND of this predicate and another. When evaluating the composed predicate, if this predicate is false, then the other predicate is not evaluated.

        Any exceptions thrown during evaluation of either predicate are relayed to the caller; if evaluation of this predicate throws an exception, the other predicate will not be evaluated.

        Parameters:
        other - a predicate that will be logically-ANDed with this predicate
        Returns:
        a composed predicate that represents the short-circuiting logical AND of this predicate and the other predicate
        Throws:
        NullPointerException - if other is null

      • negate

        default Predicate<T> negate()
        Returns a predicate that represents the logical negation of this predicate.
        Returns:
        a predicate that represents the logical negation of this predicate

      • or

        default Predicate<T> or(Predicate<? super T> other)
        Returns a composed predicate that represents a short-circuiting logical OR of this predicate and another. When evaluating the composed predicate, if this predicate is true, then the other predicate is not evaluated.

        Any exceptions thrown during evaluation of either predicate are relayed to the caller; if evaluation of this predicate throws an exception, the other predicate will not be evaluated.

        Parameters:
        other - a predicate that will be logically-ORed with this predicate
        Returns:
        a composed predicate that represents the short-circuiting logical OR of this predicate and the other predicate
        Throws:
        NullPointerException - if other is null

      • isEqual

        static <T> Predicate<T> isEqual(Object targetRef)
        Returns a predicate that tests if two arguments are equal according to Objects.equals(Object, Object).
        Type Parameters:
        T - the type of arguments to the predicate
        Parameters:
        targetRef - the object reference with which to compare for equality, which may be null
        Returns:
        a predicate that tests if two arguments are equal according to Objects.equals(Object, Object)