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 */ 029public final class IdentityPredicate<T> implements Predicate<T>, Serializable { 030 031 /** Serial version UID */ 032 private static final long serialVersionUID = -89901658494523293L; 033 034 /** 035 * Factory to create the identity predicate. 036 * 037 * @param <T> the type that the predicate queries 038 * @param object the object to compare to 039 * @return the predicate 040 */ 041 public static <T> Predicate<T> identityPredicate(final T object) { 042 if (object == null) { 043 return NullPredicate.<T>nullPredicate(); 044 } 045 return new IdentityPredicate<>(object); 046 } 047 048 /** The value to compare to */ 049 private final T iValue; 050 051 /** 052 * Constructor that performs no validation. 053 * Use {@code identityPredicate} if you want that. 054 * 055 * @param object the object to compare to 056 */ 057 public IdentityPredicate(final T object) { 058 iValue = object; 059 } 060 061 /** 062 * Evaluates the predicate returning true if the input object is identical to 063 * the stored object. 064 * 065 * @param object the input object 066 * @return true if input is the same object as the stored value 067 */ 068 @Override 069 public boolean evaluate(final T object) { 070 return iValue == object; 071 } 072 073 /** 074 * Gets the value. 075 * 076 * @return the value 077 * @since 3.1 078 */ 079 public T getValue() { 080 return iValue; 081 } 082 083}