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 import java.util.Objects; 21 22 import org.apache.commons.collections4.FunctorException; 23 import org.apache.commons.collections4.Predicate; 24 25 /** 26 * Predicate implementation that throws an exception if the input is null. 27 * 28 * @since 3.0 29 */ 30 public final class NullIsExceptionPredicate<T> implements PredicateDecorator<T>, Serializable { 31 32 /** Serial version UID */ 33 private static final long serialVersionUID = 3243449850504576071L; 34 35 /** 36 * Factory to create the null exception predicate. 37 * 38 * @param <T> the type that the predicate queries 39 * @param predicate the predicate to decorate, not null 40 * @return the predicate 41 * @throws NullPointerException if the predicate is null 42 */ 43 public static <T> Predicate<T> nullIsExceptionPredicate(final Predicate<? super T> predicate) { 44 return new NullIsExceptionPredicate<>(Objects.requireNonNull(predicate, "predicate")); 45 } 46 47 /** The predicate to decorate */ 48 private final Predicate<? super T> iPredicate; 49 50 /** 51 * Constructor that performs no validation. 52 * Use {@code nullIsExceptionPredicate} if you want that. 53 * 54 * @param predicate the predicate to call after the null check 55 */ 56 public NullIsExceptionPredicate(final Predicate<? super T> predicate) { 57 iPredicate = predicate; 58 } 59 60 /** 61 * Evaluates the predicate returning the result of the decorated predicate 62 * once a null check is performed. 63 * 64 * @param object the input object 65 * @return true if decorated predicate returns true 66 * @throws FunctorException if input is null 67 */ 68 @Override 69 public boolean evaluate(final T object) { 70 if (object == null) { 71 throw new FunctorException("Input Object must not be null"); 72 } 73 return iPredicate.evaluate(object); 74 } 75 76 /** 77 * Gets the predicate being decorated. 78 * 79 * @return the predicate as the only element in an array 80 * @since 3.1 81 */ 82 @Override 83 @SuppressWarnings("unchecked") 84 public Predicate<? super T>[] getPredicates() { 85 return new Predicate[] { iPredicate }; 86 } 87 88 }