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.Closure; 022 import org.apache.commons.collections.Transformer; 023 024 /** 025 * Closure implementation that calls a Transformer using the input object 026 * and ignore the result. 027 * 028 * @since Commons Collections 3.0 029 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 030 * 031 * @author Stephen Colebourne 032 */ 033 public class TransformerClosure implements Closure, Serializable { 034 035 /** Serial version UID */ 036 private static final long serialVersionUID = -5194992589193388969L; 037 038 /** The transformer to wrap */ 039 private final Transformer iTransformer; 040 041 /** 042 * Factory method that performs validation. 043 * <p> 044 * A null transformer will return the <code>NOPClosure</code>. 045 * 046 * @param transformer the transformer to call, null means nop 047 * @return the <code>transformer</code> closure 048 */ 049 public static Closure getInstance(Transformer transformer) { 050 if (transformer == null) { 051 return NOPClosure.INSTANCE; 052 } 053 return new TransformerClosure(transformer); 054 } 055 056 /** 057 * Constructor that performs no validation. 058 * Use <code>getInstance</code> if you want that. 059 * 060 * @param transformer the transformer to call, not null 061 */ 062 public TransformerClosure(Transformer transformer) { 063 super(); 064 iTransformer = transformer; 065 } 066 067 /** 068 * Executes the closure by calling the decorated transformer. 069 * 070 * @param input the input object 071 */ 072 public void execute(Object input) { 073 iTransformer.transform(input); 074 } 075 076 /** 077 * Gets the transformer. 078 * 079 * @return the transformer 080 * @since Commons Collections 3.1 081 */ 082 public Transformer getTransformer() { 083 return iTransformer; 084 } 085 086 }