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 * Licensed to the Apache Software Foundation (ASF) under one or more
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 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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package org.apache.commons.lang3.function;

import java.util.Objects;
import java.util.function.Predicate;

A functional interface like Predicate that declares a Throwable.
Type parameters:
  • <T> – Predicate type.
  • <E> – Thrown exception.
Since:3.11
/** * A functional interface like {@link Predicate} that declares a {@code Throwable}. * * @param <T> Predicate type. * @param <E> Thrown exception. * @since 3.11 */
@FunctionalInterface public interface FailablePredicate<T, E extends Throwable> {
FALSE singleton
/** FALSE singleton */
@SuppressWarnings("rawtypes") FailablePredicate FALSE = t -> false;
TRUE singleton
/** TRUE singleton */
@SuppressWarnings("rawtypes") FailablePredicate TRUE = t -> true;
Returns The FALSE singleton.
Type parameters:
  • <T> – Predicate type.
  • <E> – Thrown exception.
Returns:The NOP singleton.
/** * Returns The FALSE singleton. * * @param <T> Predicate type. * @param <E> Thrown exception. * @return The NOP singleton. */
static <T, E extends Throwable> FailablePredicate<T, E> falsePredicate() { return FALSE; }
Returns The FALSE TRUE.
Type parameters:
  • <T> – Predicate type.
  • <E> – Thrown exception.
Returns:The NOP singleton.
/** * Returns The FALSE TRUE. * * @param <T> Predicate type. * @param <E> Thrown exception. * @return The NOP singleton. */
static <T, E extends Throwable> FailablePredicate<T, E> truePredicate() { return TRUE; }
Returns a composed FailablePredicate like Predicate.and(Predicate).
Params:
  • other – a predicate that will be logically-ANDed with this predicate.
Throws:
Returns:a composed FailablePredicate like Predicate.and(Predicate).
/** * Returns a composed {@code FailablePredicate} like {@link Predicate#and(Predicate)}. * * @param other a predicate that will be logically-ANDed with this predicate. * @return a composed {@code FailablePredicate} like {@link Predicate#and(Predicate)}. * @throws NullPointerException if other is null */
default FailablePredicate<T, E> and(final FailablePredicate<? super T, E> other) { Objects.requireNonNull(other); return t -> test(t) && other.test(t); }
Returns a predicate that negates this predicate.
Returns:a predicate that negates this predicate.
/** * Returns a predicate that negates this predicate. * * @return a predicate that negates this predicate. */
default FailablePredicate<T, E> negate() { return t -> !test(t); }
Returns a composed FailablePredicate like Predicate.and(Predicate).
Params:
  • other – a predicate that will be logically-ORed with this predicate.
Throws:
Returns:a composed FailablePredicate like Predicate.and(Predicate).
/** * Returns a composed {@code FailablePredicate} like {@link Predicate#and(Predicate)}. * * @param other a predicate that will be logically-ORed with this predicate. * @return a composed {@code FailablePredicate} like {@link Predicate#and(Predicate)}. * @throws NullPointerException if other is null */
default FailablePredicate<T, E> or(final FailablePredicate<? super T, E> other) { Objects.requireNonNull(other); return t -> test(t) || other.test(t); }
Tests the predicate.
Params:
  • object – the object to test the predicate on
Throws:
  • E – if the predicate fails
Returns:the predicate's evaluation
/** * Tests the predicate. * * @param object the object to test the predicate on * @return the predicate's evaluation * @throws E if the predicate fails */
boolean test(T object) throws E; }