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 */ 017package org.apache.commons.functor.core.comparator; 018 019import java.util.Comparator; 020 021import org.apache.commons.functor.BinaryPredicate; 022import org.apache.commons.functor.Predicate; 023import org.apache.commons.functor.adapter.RightBoundPredicate; 024import org.apache.commons.lang3.Validate; 025 026/** 027 * A {@link BinaryPredicate BinaryPredicate} that {@link #test tests} 028 * <code>true</code> iff the left argument is greater than or equal 029 * to the right argument under the specified {@link Comparator}. 030 * When no (or a <code>null</code> <code>Comparator</code> is specified, 031 * a {@link Comparable Comparable} <code>Comparator</code> is used. 032 * 033 * @param <T> the binary predicate input types 034 * @version $Revision: 1537901 $ $Date: 2013-11-01 12:30:19 +0100 (Fr, 01 Nov 2013) $ 035 */ 036public final class IsGreaterThanOrEqual<T> implements BinaryPredicate<T, T> { 037 038 /** 039 * Basic IsGreaterThanOrEqual instance. 040 */ 041 public static final IsGreaterThanOrEqual<Comparable<?>> INSTANCE = IsGreaterThanOrEqual 042 .<Comparable<?>> instance(); 043 044 /** 045 * The wrapped comparator. 046 */ 047 private final Comparator<? super T> comparator; 048 049 /** 050 * Construct a <code>IsGreaterThanOrEqual</code> {@link BinaryPredicate predicate} 051 * for {@link Comparable Comparable}s. 052 */ 053 @SuppressWarnings("unchecked") 054 public IsGreaterThanOrEqual() { 055 this((Comparator<? super T>) ComparableComparator.INSTANCE); 056 } 057 058 /** 059 * Construct a <code>IsGreaterThanOrEqual</code> {@link BinaryPredicate predicate} 060 * for the given {@link Comparator Comparator}. 061 * 062 * @param comparator the {@link Comparator Comparator}, when <code>null</code>, 063 * a <code>Comparator</code> for {@link Comparable Comparable}s will 064 * be used. 065 */ 066 public IsGreaterThanOrEqual(Comparator<? super T> comparator) { 067 this.comparator = Validate.notNull(comparator, "Comparator argument must not be null"); 068 } 069 070 /** 071 * Return <code>true</code> iff the <i>left</i> parameter is 072 * greater than or equal to the <i>right</i> parameter under my current 073 * {@link Comparator Comparator}. 074 * {@inheritDoc} 075 */ 076 public boolean test(T left, T right) { 077 return comparator.compare(left, right) >= 0; 078 } 079 080 /** 081 * {@inheritDoc} 082 */ 083 @Override 084 public boolean equals(Object obj) { 085 if (obj == this) { 086 return true; 087 } 088 if (!(obj instanceof IsGreaterThanOrEqual<?>)) { 089 return false; 090 } 091 IsGreaterThanOrEqual<?> that = (IsGreaterThanOrEqual<?>) obj; 092 return this.comparator.equals(that.comparator); 093 } 094 095 /** 096 * {@inheritDoc} 097 */ 098 @Override 099 public int hashCode() { 100 int hash = "IsGreaterThanOrEqual".hashCode(); 101 // by construction, comparator is never null 102 hash ^= comparator.hashCode(); 103 return hash; 104 } 105 106 /** 107 * {@inheritDoc} 108 */ 109 @Override 110 public String toString() { 111 return "IsGreaterThanOrEqual<" + comparator + ">"; 112 } 113 114 /** 115 * Get a typed IsGreaterThanOrEqual instance. 116 * 117 * @param <T> the binary predicate input types 118 * @return IsGreaterThanOrEqual<T> 119 */ 120 public static <T extends Comparable<?>> IsGreaterThanOrEqual<T> instance() { 121 return new IsGreaterThanOrEqual<T>(); 122 } 123 124 /** 125 * Get an IsGreaterThanOrEqual Predicate. 126 * 127 * @param <T> the binary predicate input types 128 * @param right the right side object of the IsGreaterThanOrEqual comparison 129 * @return Predicate 130 */ 131 public static <T extends Comparable<?>> Predicate<T> instance(T right) { 132 return RightBoundPredicate.bind(new IsGreaterThanOrEqual<T>(), right); 133 } 134 135}