com.groupbyinc.common.apache.commons.collections4.functors.OnePredicate Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* 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
*
* 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.apache.commons.collections4.functors;
import java.util.Collection;
import org.apache.commons.collections4.Predicate;
/**
* Predicate implementation that returns true if only one of the
* predicates return true.
* If the array of predicates is empty, then this predicate returns false.
*
* NOTE: In versions prior to 3.2 an array size of zero or one
* threw an exception.
*
* @since 3.0
* @version $Id: OnePredicate.java 1686855 2015-06-22 13:00:27Z tn $
*/
public final class OnePredicate extends AbstractQuantifierPredicate {
/** Serial version UID */
private static final long serialVersionUID = -8125389089924745785L;
/**
* Factory to create the predicate.
*
* If the array is size zero, the predicate always returns false.
* If the array is size one, then that predicate is returned.
*
* @param the type that the predicate queries
* @param predicates the predicates to check, cloned, not null
* @return the any predicate
* @throws NullPointerException if the predicates array is null
* @throws NullPointerException if any predicate in the array is null
*/
@SuppressWarnings("unchecked")
public static Predicate onePredicate(final Predicate... predicates) {
FunctorUtils.validate(predicates);
if (predicates.length == 0) {
return FalsePredicate.falsePredicate();
}
if (predicates.length == 1) {
return (Predicate) predicates[0];
}
return new OnePredicate(FunctorUtils.copy(predicates));
}
/**
* Factory to create the predicate.
*
* @param the type that the predicate queries
* @param predicates the predicates to check, cloned, not null
* @return the one predicate
* @throws NullPointerException if the predicates array is null
* @throws NullPointerException if any predicate in the array is null
*/
public static Predicate onePredicate(final Collection> predicates) {
final Predicate[] preds = FunctorUtils.validate(predicates);
return new OnePredicate(preds);
}
/**
* Constructor that performs no validation.
* Use onePredicate if you want that.
*
* @param predicates the predicates to check, not cloned, not null
*/
public OnePredicate(final Predicate... predicates) {
super(predicates);
}
/**
* Evaluates the predicate returning true if only one decorated predicate
* returns true.
*
* @param object the input object
* @return true if only one decorated predicate returns true
*/
public boolean evaluate(final T object) {
boolean match = false;
for (final Predicate iPredicate : iPredicates) {
if (iPredicate.evaluate(object)) {
if (match) {
return false;
}
match = true;
}
}
return match;
}
}