/*
* 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.FunctorException;
import org.apache.commons.collections.Transformer;
/**
* Transformer implementation that always throws an exception.
*
* @since Commons Collections 3.0
* @version $Revision: 1.7 $ $Date: 2004/05/16 11:36:31 $
*
* @author Stephen Colebourne
*/
public final class ExceptionTransformer implements Transformer, Serializable {
/** Serial version UID */
static final long serialVersionUID = 7179106032121985545L;
/** Singleton predicate instance */
public static final Transformer INSTANCE = new ExceptionTransformer();
/**
* Factory returning the singleton instance.
*
* @return the singleton instance
* @since Commons Collections 3.1
*/
public static Transformer getInstance() {
return INSTANCE;
}
/**
* Restricted constructor.
*/
private ExceptionTransformer() {
super();
}
/**
* Transforms the input to result by cloning it.
*
* @param input the input object to transform
* @return never
* @throws FunctorException always
*/
public Object transform(Object input) {
throw new FunctorException("ExceptionTransformer invoked");
}
}