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/*
* 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.tomcat.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;
}
/**
* NO-OP method provided to enable simple pre-loading of this class. Since
* the class is used extensively in error handling, it is prudent to
* pre-load it to avoid any failure to load this class masking the true
* problem during error handling.
*/
public static void preload() {
// NO-OP
}
}
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