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      1 /*
      2  * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/util/ExceptionUtils.java $
      3  * $Revision: 613003 $
      4  * $Date: 2008-01-17 15:00:42 -0800 (Thu, 17 Jan 2008) $
      5  *
      6  * ====================================================================
      7  * Licensed to the Apache Software Foundation (ASF) under one
      8  * or more contributor license agreements.  See the NOTICE file
      9  * distributed with this work for additional information
     10  * regarding copyright ownership.  The ASF licenses this file
     11  * to you under the Apache License, Version 2.0 (the
     12  * "License"); you may not use this file except in compliance
     13  * with the License.  You may obtain a copy of the License at
     14  *
     15  *   http://www.apache.org/licenses/LICENSE-2.0
     16  *
     17  * Unless required by applicable law or agreed to in writing,
     18  * software distributed under the License is distributed on an
     19  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     20  * KIND, either express or implied.  See the License for the
     21  * specific language governing permissions and limitations
     22  * under the License.
     23  * ====================================================================
     24  *
     25  * This software consists of voluntary contributions made by many
     26  * individuals on behalf of the Apache Software Foundation.  For more
     27  * information on the Apache Software Foundation, please see
     28  * <http://www.apache.org/>.
     29  *
     30  */
     31 package org.apache.http.util;
     32 
     33 import java.lang.reflect.Method;
     34 
     35 /**
     36  * The home for utility methods that handle various exception-related tasks.
     37  *
     38  * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
     39  * @author <a href="mailto:laura (at) lwerner.org">Laura Werner</a>
     40  *
     41  * @since 4.0
     42  *
     43  * @deprecated Please use {@link java.net.URL#openConnection} instead.
     44  *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
     45  *     for further details.
     46  */
     47 @Deprecated
     48 public final class ExceptionUtils {
     49 
     50     /** A reference to Throwable's initCause method, or null if it's not there in this JVM */
     51     static private final Method INIT_CAUSE_METHOD = getInitCauseMethod();
     52 
     53     /**
     54      * Returns a <code>Method<code> allowing access to
     55      * {@link Throwable#initCause(Throwable) initCause} method of {@link Throwable},
     56      * or <code>null</code> if the method
     57      * does not exist.
     58      *
     59      * @return A <code>Method<code> for <code>Throwable.initCause</code>, or
     60      * <code>null</code> if unavailable.
     61      */
     62     static private Method getInitCauseMethod() {
     63         try {
     64             Class[] paramsClasses = new Class[] { Throwable.class };
     65             return Throwable.class.getMethod("initCause", paramsClasses);
     66         } catch (NoSuchMethodException e) {
     67             return null;
     68         }
     69     }
     70 
     71     /**
     72      * If we're running on JDK 1.4 or later, initialize the cause for the given throwable.
     73      *
     74      * @param  throwable The throwable.
     75      * @param  cause     The cause of the throwable.
     76      */
     77     public static void initCause(Throwable throwable, Throwable cause) {
     78         if (INIT_CAUSE_METHOD != null) {
     79             try {
     80                 INIT_CAUSE_METHOD.invoke(throwable, new Object[] { cause });
     81             } catch (Exception e) {
     82                 // Well, with no logging, the only option is to munch the exception
     83             }
     84         }
     85     }
     86 
     87     private ExceptionUtils() {
     88     }
     89 
     90 }
     91