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.collections4.functors; 018 019import java.io.Serializable; 020 021import org.apache.commons.collections4.Predicate; 022 023/** 024 * Predicate implementation that returns true if the input is the same object 025 * as the one stored in this predicate. 026 * 027 * @since 3.0 028 * @version $Id: IdentityPredicate.html 972421 2015-11-14 20:00:04Z tn $ 029 */ 030public final class IdentityPredicate<T> implements Predicate<T>, Serializable { 031 032 /** Serial version UID */ 033 private static final long serialVersionUID = -89901658494523293L; 034 035 /** The value to compare to */ 036 private final T iValue; 037 038 /** 039 * Factory to create the identity predicate. 040 * 041 * @param <T> the type that the predicate queries 042 * @param object the object to compare to 043 * @return the predicate 044 * @throws IllegalArgumentException if the predicate is null 045 */ 046 public static <T> Predicate<T> identityPredicate(final T object) { 047 if (object == null) { 048 return NullPredicate.<T>nullPredicate(); 049 } 050 return new IdentityPredicate<T>(object); 051 } 052 053 /** 054 * Constructor that performs no validation. 055 * Use <code>identityPredicate</code> if you want that. 056 * 057 * @param object the object to compare to 058 */ 059 public IdentityPredicate(final T object) { 060 super(); 061 iValue = object; 062 } 063 064 /** 065 * Evaluates the predicate returning true if the input object is identical to 066 * the stored object. 067 * 068 * @param object the input object 069 * @return true if input is the same object as the stored value 070 */ 071 public boolean evaluate(final T object) { 072 return iValue == object; 073 } 074 075 /** 076 * Gets the value. 077 * 078 * @return the value 079 * @since 3.1 080 */ 081 public T getValue() { 082 return iValue; 083 } 084 085}