org.testifyproject.glassfish.jersey.internal.guava.Predicates Maven / Gradle / Ivy
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in org.testifyproject.testifyprojectpliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org.testifyproject/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.testifyproject.glassfish.org.testifyproject.internal.guava;
import java.io.Serializable;
import java.util.Collection;
import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;
import static org.testifyproject.glassfish.org.testifyproject.internal.guava.Preconditions.checkNotNull;
/**
* Static utility methods pertaining to {@code Predicate} instances.
*
*
All methods returns serializable predicates as long as they're given
* serializable parameters.
*
*
See the Guava User Guide article on the
* use of {@code Predicate}.
*
* @author Kevin Bourrillion
* @since 2.0 (imported from Google Collections Library)
*/
public final class Predicates {
private static final Joiner COMMA_JOINER = Joiner.on();
// TODO(kevinb): considering having these implement a VisitablePredicate
// interface which specifies an accept(PredicateVisitor) method.
private Predicates() {
}
/**
* Returns a predicate that always evaluates to {@code true}.
*/
public static Predicate alwaysTrue() {
return ObjectPredicate.ALWAYS_TRUE.withNarrowedType();
}
/**
* Returns a predicate that evaluates to {@code true} if the object reference
* being tested is null.
*/
private static Predicate isNull() {
return ObjectPredicate.IS_NULL.withNarrowedType();
}
/**
* Returns a predicate that evaluates to {@code true} if the given predicate
* evaluates to {@code false}.
*/
public static Predicate not(Predicate predicate) {
return new NotPredicate(predicate);
}
/**
* Returns a predicate that evaluates to {@code true} if the object being
* tested {@code equals()} the given target or both are null.
*/
public static Predicate equalTo(T target) {
return (target == null)
? Predicates.isNull()
: new IsEqualToPredicate(target);
}
/**
* Returns a predicate that evaluates to {@code true} if the object reference
* being tested is a member of the given collection. It does not defensively
* copy the collection passed in, so future changes to it will alter the
* behavior of the predicate.
*
*
This method can technically accept any {@code Collection>}, but using
* a typed collection helps prevent bugs. This approach doesn't block any
* potential users since it is always possible to use {@code
* Predicates.