/*
 * 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.batchee.container.util;

/**
 * This class is taken from Apache OpenWebBeans.
 *
 * It instantly re-throws any Exception as if it would be a RuntimeException
 */
public class ExceptionUtil {
    private ExceptionUtil() {
        // prevent instantiation
    }

    public static RuntimeException throwAsRuntimeException(Throwable throwable) {
        //Attention: helper which allows to use a trick to throw
        // a catched checked exception without a wrapping exception
        new ExceptionHelper<RuntimeException>().throwException(throwable);

        return null; //not needed due to the helper trick, but it's easier for using it
    }

    @SuppressWarnings({"unchecked"})
    private static class ExceptionHelper<T extends Throwable> {
        private void throwException(Throwable exception) throws T {
            try {
                //exception-type is only checked at compile-time
                throw (T) exception;
            } catch (ClassCastException e) {
                //doesn't happen with existing JVMs! - if that changes the local ClassCastException needs to be ignored
                //-> throw original exception
                if (e.getStackTrace()[0].toString().contains(getClass().getName())) {
                    if (exception instanceof RuntimeException) {
                        throw (RuntimeException) exception;
                    }
                    throw new RuntimeException(exception);
                }
                //if the exception to throw is a ClassCastException, throw it
                throw e;
            }
        }
    }
}
