Predicate

  • Predicate is a functional interface representing a boolean-valued function of one argument.

  • Its primary function is test(T t), which evaluates the predicate on a given input and returns true or false.

  • It provides methods like and, or, and negate to combine or modify predicates.

  • The isEqual method creates a predicate that checks for equality between two objects using Objects.equals.
public interface Predicate

Represents a predicate (boolean-valued function) of one argument.

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

Public Method Summary

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).
Predicate<T>
negate()
Returns a predicate that represents the logical negation of this predicate.
Predicate<T>
or(Predicate<? super T> other)
Returns a composed predicate that represents a short-circuiting logical OR of this predicate and another.
abstract boolean
test(T t)
Evaluates this predicate on the given argument.

Public Methods

public 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

public static Predicate<T> isEqual (Object targetRef)

Returns a predicate that tests if two arguments are equal according to Objects.equals(Object, Object).

Parameters
targetRef the object reference with which to compare for equality, which may be null
Returns

public 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

public 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

public abstract 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