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; 020import java.util.Objects; 021 022import org.apache.commons.collections4.FunctorException; 023import org.apache.commons.collections4.Predicate; 024 025/** 026 * Predicate implementation that throws an exception if the input is null. 027 * 028 * @since 3.0 029 */ 030public final class NullIsExceptionPredicate<T> implements PredicateDecorator<T>, Serializable { 031 032 /** Serial version UID */ 033 private static final long serialVersionUID = 3243449850504576071L; 034 035 /** 036 * Factory to create the null exception predicate. 037 * 038 * @param <T> the type that the predicate queries 039 * @param predicate the predicate to decorate, not null 040 * @return the predicate 041 * @throws NullPointerException if the predicate is null 042 */ 043 public static <T> Predicate<T> nullIsExceptionPredicate(final Predicate<? super T> predicate) { 044 return new NullIsExceptionPredicate<>(Objects.requireNonNull(predicate, "predicate")); 045 } 046 047 /** The predicate to decorate */ 048 private final Predicate<? super T> iPredicate; 049 050 /** 051 * Constructor that performs no validation. 052 * Use {@code nullIsExceptionPredicate} if you want that. 053 * 054 * @param predicate the predicate to call after the null check 055 */ 056 public NullIsExceptionPredicate(final Predicate<? super T> predicate) { 057 iPredicate = predicate; 058 } 059 060 /** 061 * Evaluates the predicate returning the result of the decorated predicate 062 * once a null check is performed. 063 * 064 * @param object the input object 065 * @return true if decorated predicate returns true 066 * @throws FunctorException if input is null 067 */ 068 @Override 069 public boolean evaluate(final T object) { 070 if (object == null) { 071 throw new FunctorException("Input Object must not be null"); 072 } 073 return iPredicate.evaluate(object); 074 } 075 076 /** 077 * Gets the predicate being decorated. 078 * 079 * @return the predicate as the only element in an array 080 * @since 3.1 081 */ 082 @Override 083 @SuppressWarnings("unchecked") 084 public Predicate<? super T>[] getPredicates() { 085 return new Predicate[] { iPredicate }; 086 } 087 088}