Java tutorial
/* * Copyright 2001-2004 The Apache Software Foundation * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.collections.functors; import java.io.Serializable; import org.apache.commons.collections.Transformer; /** * Transformer implementation that does nothing. * * @since Commons Collections 3.0 * @version $Revision: 1.6 $ $Date: 2004/05/16 11:36:31 $ * * @author Stephen Colebourne */ public class NOPTransformer implements Transformer, Serializable { /** Serial version UID */ static final long serialVersionUID = 2133891748318574490L; /** Singleton predicate instance */ public static final Transformer INSTANCE = new NOPTransformer(); /** * Factory returning the singleton instance. * * @return the singleton instance * @since Commons Collections 3.1 */ public static Transformer getInstance() { return INSTANCE; } /** * Constructor */ private NOPTransformer() { super(); } /** * Transforms the input to result by doing nothing. * * @param input the input object to transform * @return the transformed result which is the input */ public Object transform(Object input) { return input; } }