/*

* 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.jasper.util;

import java.lang.reflect.InvocationTargetException;

/**

* Utilities for handling Throwables and Exceptions.

*/

public class ExceptionUtils {

/**

* Checks whether the supplied Throwable is one that needs to be

* rethrown and swallows all others.

* @param t the Throwable to check

*/

public static void handleThrowable(Throwable t) {

if (t instanceof ThreadDeath) {

throw (ThreadDeath) t;

}

if (t instanceof StackOverflowError) {

// Swallow silently - it should be recoverable

return;

}

if (t instanceof VirtualMachineError) {

throw (VirtualMachineError) t;

}

// All other instances of Throwable will be silently swallowed

}

/**

* Checks whether the supplied Throwable is an instance of

* <code>InvocationTargetException</code> and returns the throwable that is

* wrapped by it, if there is any.

*

* @param t the Throwable to check

* @return <code>t</code> or <code>t.getCause()</code>

*/

public static Throwable unwrapInvocationTargetException(Throwable t) {

if (t instanceof InvocationTargetException && t.getCause() != null) {

return t.getCause();

}

return t;

}

}