| /* |
| * 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; |
| |
| /** |
| * Defines a functor interface implemented by classes that transform one |
| * object into another. |
| * <p> |
| * A <code>Transformer</code> converts the input object to the output object. |
| * The input object should be left unchanged. |
| * Transformers are typically used for type conversions, or extracting data |
| * from an object. |
| * <p> |
| * Standard implementations of common transformers are provided by |
| * {@link TransformerUtils}. These include method invokation, returning a constant, |
| * cloning and returning the string value. |
| * |
| * @since Commons Collections 1.0 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:19 $ |
| * |
| * @author James Strachan |
| * @author Stephen Colebourne |
| */ |
| public interface Transformer { |
| |
| /** |
| * Transforms the input object (leaving it unchanged) into some output object. |
| * |
| * @param input the object to be transformed, should be left unchanged |
| * @return a transformed object |
| * @throws ClassCastException (runtime) if the input is the wrong class |
| * @throws IllegalArgumentException (runtime) if the input is invalid |
| * @throws FunctorException (runtime) if the transform cannot be completed |
| */ |
| public Object transform(Object input); |
| |
| } |
