001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.commons.collections.functors;
018
019 import java.io.Serializable;
020 import java.util.Collection;
021
022 import org.apache.commons.collections.Predicate;
023
024 /**
025 * Predicate implementation that returns true if none of the
026 * predicates return true.
027 * If the array of predicates is empty, then this predicate returns true.
028 * <p>
029 * NOTE: In versions prior to 3.2 an array size of zero or one
030 * threw an exception.
031 *
032 * @since Commons Collections 3.0
033 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
034 *
035 * @author Stephen Colebourne
036 * @author Matt Benson
037 */
038 public final class NonePredicate implements Predicate, PredicateDecorator, Serializable {
039
040 /** Serial version UID */
041 private static final long serialVersionUID = 2007613066565892961L;
042
043 /** The array of predicates to call */
044 private final Predicate[] iPredicates;
045
046 /**
047 * Factory to create the predicate.
048 * <p>
049 * If the array is size zero, the predicate always returns true.
050 *
051 * @param predicates the predicates to check, cloned, not null
052 * @return the <code>any</code> predicate
053 * @throws IllegalArgumentException if the predicates array is null
054 * @throws IllegalArgumentException if any predicate in the array is null
055 */
056 public static Predicate getInstance(Predicate[] predicates) {
057 FunctorUtils.validate(predicates);
058 if (predicates.length == 0) {
059 return TruePredicate.INSTANCE;
060 }
061 predicates = FunctorUtils.copy(predicates);
062 return new NonePredicate(predicates);
063 }
064
065 /**
066 * Factory to create the predicate.
067 * <p>
068 * If the collection is size zero, the predicate always returns true.
069 *
070 * @param predicates the predicates to check, cloned, not null
071 * @return the <code>one</code> predicate
072 * @throws IllegalArgumentException if the predicates array is null
073 * @throws IllegalArgumentException if any predicate in the array is null
074 */
075 public static Predicate getInstance(Collection predicates) {
076 Predicate[] preds = FunctorUtils.validate(predicates);
077 if (preds.length == 0) {
078 return TruePredicate.INSTANCE;
079 }
080 return new NonePredicate(preds);
081 }
082
083 /**
084 * Constructor that performs no validation.
085 * Use <code>getInstance</code> if you want that.
086 *
087 * @param predicates the predicates to check, not cloned, not null
088 */
089 public NonePredicate(Predicate[] predicates) {
090 super();
091 iPredicates = predicates;
092 }
093
094 /**
095 * Evaluates the predicate returning false if any stored predicate returns false.
096 *
097 * @param object the input object
098 * @return true if none of decorated predicates return true
099 */
100 public boolean evaluate(Object object) {
101 for (int i = 0; i < iPredicates.length; i++) {
102 if (iPredicates[i].evaluate(object)) {
103 return false;
104 }
105 }
106 return true;
107 }
108
109 /**
110 * Gets the predicates, do not modify the array.
111 *
112 * @return the predicates
113 * @since Commons Collections 3.1
114 */
115 public Predicate[] getPredicates() {
116 return iPredicates;
117 }
118
119 }