1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27 package org.apache.http.util;
28
29 import java.lang.reflect.Method;
30
31 /**
32 * The home for utility methods that handle various exception-related tasks.
33 *
34 *
35 * @since 4.0
36 *
37 * @deprecated (4.2) no longer used
38 */
39 @Deprecated
40 public final class ExceptionUtils {
41
42 /** A reference to Throwable's initCause method, or null if it's not there in this JVM */
43 static private final Method INIT_CAUSE_METHOD = getInitCauseMethod();
44
45 /**
46 * Returns a {@code Method} allowing access to
47 * {@link Throwable#initCause(Throwable) initCause} method of {@link Throwable},
48 * or {@code null} if the method
49 * does not exist.
50 *
51 * @return A {@code Method} for {@code Throwable.initCause}, or
52 * {@code null} if unavailable.
53 */
54 static private Method getInitCauseMethod() {
55 try {
56 final Class<?>[] paramsClasses = new Class[] { Throwable.class };
57 return Throwable.class.getMethod("initCause", paramsClasses);
58 } catch (final NoSuchMethodException e) {
59 return null;
60 }
61 }
62
63 /**
64 * If we're running on JDK 1.4 or later, initialize the cause for the given throwable.
65 *
66 * @param throwable The throwable.
67 * @param cause The cause of the throwable.
68 */
69 public static void initCause(final Throwable throwable, final Throwable cause) {
70 if (INIT_CAUSE_METHOD != null) {
71 try {
72 INIT_CAUSE_METHOD.invoke(throwable, cause);
73 } catch (final Exception e) {
74 // Well, with no logging, the only option is to munch the exception
75 }
76 }
77 }
78
79 private ExceptionUtils() {
80 }
81
82 }