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 */ 017 package org.apache.commons.collections.functors; 018 019 import java.io.Serializable; 020 021 import org.apache.commons.collections.Predicate; 022 023 /** 024 * Predicate implementation that returns true if the input is not null. 025 * 026 * @since Commons Collections 3.0 027 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 028 * 029 * @author Stephen Colebourne 030 */ 031 public final class NotNullPredicate implements Predicate, Serializable { 032 033 /** Serial version UID */ 034 private static final long serialVersionUID = 7533784454832764388L; 035 036 /** Singleton predicate instance */ 037 public static final Predicate INSTANCE = new NotNullPredicate(); 038 039 /** 040 * Factory returning the singleton instance. 041 * 042 * @return the singleton instance 043 * @since Commons Collections 3.1 044 */ 045 public static Predicate getInstance() { 046 return INSTANCE; 047 } 048 049 /** 050 * Restricted constructor. 051 */ 052 private NotNullPredicate() { 053 super(); 054 } 055 056 /** 057 * Evaluates the predicate returning true if the object does not equal null. 058 * 059 * @param object the object to evaluate 060 * @return true if not null 061 */ 062 public boolean evaluate(Object object) { 063 return (object != null); 064 } 065 066 }