Module java.base
Package 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.

    @FunctionalInterfacepublic interfacePredicate<T>
    Represents a predicate (boolean-valued function) of one argument.

    This is afunctional interface whose functional method istest(Object).

    Since:
    1.8
    • 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, otherwisefalse
      • and

        default Predicate<T> and​(Predicate<? superT> 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 isfalse, then theother 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, theother 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 theother 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<? superT> 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 istrue, then theother 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, theother 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 theother 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 toObjects.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 benull
        Returns:
        a predicate that tests if two arguments are equal according toObjects.equals(Object, Object)
      • not

        static <T> Predicate<T> not​(Predicate<? super T> target)
        Returns a predicate that is the negation of the supplied predicate. This is accomplished by returning result of the callingtarget.negate().
        Type Parameters:
        T - the type of arguments to the specified predicate
        Parameters:
        target - predicate to negate
        Returns:
        a predicate that negates the results of the supplied predicate
        Throws:
        NullPointerException - if target is null
        Since:
        11