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.functor.core.comparator;
018
019 import java.io.Serializable;
020 import org.apache.commons.functor.UnaryPredicate;
021
022 /**
023 * A {@link UnaryPredicate} that tests whether a {@link Comparable} object is
024 * within a range. The range is defined in the constructor.
025 *
026 * @since 1.0
027 * @version $Revision: 1171154 $ $Date: 2011-09-15 17:58:38 +0200 (Thu, 15 Sep 2011) $
028 * @author Jason Horman (jason@jhorman.org)
029 */
030
031 public class IsWithinRange<A extends Comparable<A>> implements UnaryPredicate<A>, Serializable {
032 /**
033 * serialVersionUID declaration.
034 */
035 private static final long serialVersionUID = -7584005207181667878L;
036
037 /** Hashcode of the name of this Predicate. */
038 private static final int NAME_HASH_CODE = "IsWithinRange".hashCode();
039
040 /** Base Hashcode. */
041 private static final int BASE_HASH_CODE = 29;
042
043 /***************************************************
044 * Instance variables
045 ***************************************************/
046
047 /** The minimum value of the range. */
048 private final A min;
049 /** The maximum value of the range. */
050 private final A max;
051
052 /***************************************************
053 * Constructors
054 ***************************************************/
055
056 /**
057 * Create a new IsWithinRange by passing in the range that will
058 * be used in the {@link #test}.
059 * @param min Comparable
060 * @param max Comparable
061 */
062 public IsWithinRange(A min, A max) {
063 if (min == null || max == null) {
064 throw new IllegalArgumentException("min and max must not be null");
065 }
066 if (min.compareTo(max) > 0) {
067 throw new IllegalArgumentException("min must be <= max");
068 }
069 this.min = min;
070 this.max = max;
071 }
072
073 /***************************************************
074 * Instance methods
075 ***************************************************/
076
077 /**
078 * {@inheritDoc}
079 * Test if the passed in object is within the specified range.
080 */
081 public final boolean test(A o) {
082 return o.compareTo(min) >= 0 && o.compareTo(max) <= 0;
083 }
084
085 /**
086 * {@inheritDoc}
087 */
088 public final boolean equals(Object o) {
089 if (this == o) {
090 return true;
091 }
092 if (!(o instanceof IsWithinRange<?>)) {
093 return false;
094 }
095 final IsWithinRange<?> isWithinRange = (IsWithinRange<?>) o;
096 return max.equals(isWithinRange.max) && min.equals(isWithinRange.min);
097 }
098
099 /**
100 * {@inheritDoc}
101 */
102 public int hashCode() {
103 return BASE_HASH_CODE * min.hashCode() + max.hashCode() + NAME_HASH_CODE;
104 }
105
106 /**
107 * {@inheritDoc}
108 */
109 public String toString() {
110 return "IsWithinRange(" + min + ", " + max + ")";
111 }
112
113 /**
114 * Obtain an IsWithinRange instance.
115 * @param <A>
116 * @param min A
117 * @param max A
118 * @return IsWithinRange<A>
119 */
120 public static <A extends Comparable<A>> IsWithinRange<A> instance(A min, A max) {
121 return new IsWithinRange<A>(min, max);
122 }
123 }