1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.collections4.functors; 18 19 import java.io.Serializable; 20 21 import org.apache.commons.collections4.Predicate; 22 23 /** 24 * Predicate implementation that returns true if the input is the same object 25 * as the one stored in this predicate. 26 * 27 * @since 3.0 28 */ 29 public final class IdentityPredicate<T> implements Predicate<T>, Serializable { 30 31 /** Serial version UID */ 32 private static final long serialVersionUID = -89901658494523293L; 33 34 /** 35 * Factory to create the identity predicate. 36 * 37 * @param <T> the type that the predicate queries 38 * @param object the object to compare to 39 * @return the predicate 40 */ 41 public static <T> Predicate<T> identityPredicate(final T object) { 42 if (object == null) { 43 return NullPredicate.<T>nullPredicate(); 44 } 45 return new IdentityPredicate<>(object); 46 } 47 48 /** The value to compare to */ 49 private final T iValue; 50 51 /** 52 * Constructor that performs no validation. 53 * Use {@code identityPredicate} if you want that. 54 * 55 * @param object the object to compare to 56 */ 57 public IdentityPredicate(final T object) { 58 iValue = object; 59 } 60 61 /** 62 * Evaluates the predicate returning true if the input object is identical to 63 * the stored object. 64 * 65 * @param object the input object 66 * @return true if input is the same object as the stored value 67 */ 68 @Override 69 public boolean evaluate(final T object) { 70 return iValue == object; 71 } 72 73 /** 74 * Gets the value. 75 * 76 * @return the value 77 * @since 3.1 78 */ 79 public T getValue() { 80 return iValue; 81 } 82 83 }