| /* |
| * $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() { |
| } |
| |
| } |