1 /**
2 * Copyright 2007 The Apache Software Foundation
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20 package org.apache.hadoop.hbase;
21
22 import java.io.IOException;
23 import java.lang.reflect.Constructor;
24 import java.lang.reflect.InvocationTargetException;
25
26 import org.apache.hadoop.ipc.RemoteException;
27
28 /**
29 * An immutable class which contains a static method for handling
30 * org.apache.hadoop.ipc.RemoteException exceptions.
31 */
32 public class RemoteExceptionHandler {
33 /* Not instantiable */
34 private RemoteExceptionHandler() {super();}
35
36 /**
37 * Examine passed Throwable. See if its carrying a RemoteException. If so,
38 * run {@link #decodeRemoteException(RemoteException)} on it. Otherwise,
39 * pass back <code>t</code> unaltered.
40 * @param t Throwable to examine.
41 * @return Decoded RemoteException carried by <code>t</code> or
42 * <code>t</code> unaltered.
43 */
44 public static Throwable checkThrowable(final Throwable t) {
45 Throwable result = t;
46 if (t instanceof RemoteException) {
47 try {
48 result =
49 RemoteExceptionHandler.decodeRemoteException((RemoteException)t);
50 } catch (Throwable tt) {
51 result = tt;
52 }
53 }
54 return result;
55 }
56
57 /**
58 * Examine passed IOException. See if its carrying a RemoteException. If so,
59 * run {@link #decodeRemoteException(RemoteException)} on it. Otherwise,
60 * pass back <code>e</code> unaltered.
61 * @param e Exception to examine.
62 * @return Decoded RemoteException carried by <code>e</code> or
63 * <code>e</code> unaltered.
64 */
65 public static IOException checkIOException(final IOException e) {
66 Throwable t = checkThrowable(e);
67 return t instanceof IOException? (IOException)t: new IOException(t);
68 }
69
70 /**
71 * Converts org.apache.hadoop.ipc.RemoteException into original exception,
72 * if possible. If the original exception is an Error or a RuntimeException,
73 * throws the original exception.
74 *
75 * @param re original exception
76 * @return decoded RemoteException if it is an instance of or a subclass of
77 * IOException, or the original RemoteException if it cannot be decoded.
78 *
79 * @throws IOException indicating a server error ocurred if the decoded
80 * exception is not an IOException. The decoded exception is set as
81 * the cause.
82 * @deprecated Use {@link RemoteException#unwrapRemoteException()} instead.
83 * In fact we should look into deprecating this whole class - St.Ack 2010929
84 */
85 public static IOException decodeRemoteException(final RemoteException re)
86 throws IOException {
87 IOException i = re;
88
89 try {
90 Class<?> c = Class.forName(re.getClassName());
91
92 Class<?>[] parameterTypes = { String.class };
93 Constructor<?> ctor = c.getConstructor(parameterTypes);
94
95 Object[] arguments = { re.getMessage() };
96 Throwable t = (Throwable) ctor.newInstance(arguments);
97
98 if (t instanceof IOException) {
99 i = (IOException) t;
100
101 } else {
102 i = new IOException("server error");
103 i.initCause(t);
104 throw i;
105 }
106
107 } catch (ClassNotFoundException x) {
108 // continue
109 } catch (NoSuchMethodException x) {
110 // continue
111 } catch (IllegalAccessException x) {
112 // continue
113 } catch (InvocationTargetException x) {
114 // continue
115 } catch (InstantiationException x) {
116 // continue
117 }
118 return i;
119 }
120 }