/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.collections15.functors;
import java.io.Serializable;
import org.apache.commons.collections15.Transformer;
import org.apache.commons.collections15.util.GWTCloneable;
/**
* Transformer implementation that returns a clone of the input object.
* <p>
* Clone is performed using
* <code>PrototypeFactory.getInstance(input).create()</code>.
*
* @since Commons Collections 3.0
* @version $Revision$ $Date$
*
* @author Stephen Colebourne
*/
public class CloneTransformer<T> implements Transformer<T, T>, Serializable {
/** Serial version UID */
private static final long serialVersionUID = -8188742709499652567L;
/** Singleton predicate instance */
public static final Transformer<Object, Object> INSTANCE = new CloneTransformer<Object>();
/**
* Factory returning the singleton instance.
*
* @return the singleton instance
* @since Commons Collections 3.1
*/
@SuppressWarnings("unchecked")
public static <T> Transformer<T, T> getInstance() {
return (Transformer<T, T>) INSTANCE;
}
/**
* Constructor
*/
private CloneTransformer() {
super();
}
/**
* Transforms the input to result by cloning it.
*
* @param input
* the input object to transform
* @return the transformed result
*/
@Override
public T transform(T input) {
if (input == null) {
return null;
}
if (input instanceof GWTCloneable) {
return (T) ((GWTCloneable) input).duplicate();
}
throw new RuntimeException("Cloning is not supported for:" + input);
}
}