/*
 * 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.collections4.functors;

import java.io.Serializable;

import org.apache.commons.collections4.FunctorException;
import org.apache.commons.collections4.Transformer;

Transformer implementation that always throws an exception.
Since:3.0
/** * Transformer implementation that always throws an exception. * * @since 3.0 */
public final class ExceptionTransformer<I, O> implements Transformer<I, O>, Serializable {
Serial version UID
/** Serial version UID */
private static final long serialVersionUID = 7179106032121985545L;
Singleton predicate instance
/** Singleton predicate instance */
@SuppressWarnings("rawtypes") // the static instance works for all types public static final Transformer INSTANCE = new ExceptionTransformer<>();
Factory returning the singleton instance.
Type parameters:
  • <I> – the input type
  • <O> – the output type
Returns:the singleton instance
Since:3.1
/** * Factory returning the singleton instance. * * @param <I> the input type * @param <O> the output type * @return the singleton instance * @since 3.1 */
@SuppressWarnings("unchecked") // the static instance works for all types public static <I, O> Transformer<I, O> exceptionTransformer() { return INSTANCE; }
Restricted constructor.
/** * Restricted constructor. */
private ExceptionTransformer() { super(); }
Transforms the input to result by cloning it.
Params:
  • input – the input object to transform
Throws:
Returns:never
/** * Transforms the input to result by cloning it. * * @param input the input object to transform * @return never * @throws FunctorException always */
@Override public O transform(final I input) { throw new FunctorException("ExceptionTransformer invoked"); } private Object readResolve() { return INSTANCE; } }