/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/util/ExceptionUtils.java $
* $Revision: 613003 $
* $Date: 2008-01-17 15:00:42 -0800 (Thu, 17 Jan 2008) $
*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.util;
import java.lang.reflect.Method;
/**
* The home for utility methods that handle various exception-related tasks.
*
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
* @author <a href="mailto:laura@lwerner.org">Laura Werner</a>
*
* @since 4.0
*/
public final class ExceptionUtils {
/** A reference to Throwable's initCause method, or null if it's not there in this JVM */
static private final Method INIT_CAUSE_METHOD = getInitCauseMethod();
/**
* Returns a <code>Method<code> allowing access to
* {@link Throwable#initCause(Throwable) initCause} method of {@link Throwable},
* or <code>null</code> if the method
* does not exist.
*
* @return A <code>Method<code> for <code>Throwable.initCause</code>, or
* <code>null</code> if unavailable.
*/
static private Method getInitCauseMethod() {
try {
Class[] paramsClasses = new Class[] { Throwable.class };
return Throwable.class.getMethod("initCause", paramsClasses);
} catch (NoSuchMethodException e) {
return null;
}
}
/**
* If we're running on JDK 1.4 or later, initialize the cause for the given throwable.
*
* @param throwable The throwable.
* @param cause The cause of the throwable.
*/
public static void initCause(Throwable throwable, Throwable cause) {
if (INIT_CAUSE_METHOD != null) {
try {
INIT_CAUSE_METHOD.invoke(throwable, new Object[] { cause });
} catch (Exception e) {
// Well, with no logging, the only option is to munch the exception
}
}
}
private ExceptionUtils() {
}
}