| /* |
| * 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. |
| */ |
| |
| package org.apache.hadoop.fs.swift.http; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.IOException; |
| import java.lang.reflect.Constructor; |
| import java.net.ConnectException; |
| import java.net.NoRouteToHostException; |
| import java.net.SocketTimeoutException; |
| import java.net.UnknownHostException; |
| |
| /** |
| * Variant of Hadoop NetUtils exception wrapping with URI awareness and |
| * available in branch-1 too. |
| */ |
| public class ExceptionDiags { |
| private static final Logger LOG = |
| LoggerFactory.getLogger(ExceptionDiags.class); |
| |
| /** text to point users elsewhere: {@value} */ |
| private static final String FOR_MORE_DETAILS_SEE |
| = " For more details see: "; |
| /** text included in wrapped exceptions if the host is null: {@value} */ |
| public static final String UNKNOWN_HOST = "(unknown)"; |
| /** Base URL of the Hadoop Wiki: {@value} */ |
| public static final String HADOOP_WIKI = "http://wiki.apache.org/hadoop/"; |
| |
| /** |
| * Take an IOException and a URI, wrap it where possible with |
| * something that includes the URI |
| * |
| * @param dest target URI |
| * @param operation operation |
| * @param exception the caught exception. |
| * @return an exception to throw |
| */ |
| public static IOException wrapException(final String dest, |
| final String operation, |
| final IOException exception) { |
| String action = operation + " " + dest; |
| String xref = null; |
| |
| if (exception instanceof ConnectException) { |
| xref = "ConnectionRefused"; |
| } else if (exception instanceof UnknownHostException) { |
| xref = "UnknownHost"; |
| } else if (exception instanceof SocketTimeoutException) { |
| xref = "SocketTimeout"; |
| } else if (exception instanceof NoRouteToHostException) { |
| xref = "NoRouteToHost"; |
| } |
| String msg = action |
| + " failed on exception: " |
| + exception; |
| if (xref != null) { |
| msg = msg + ";" + see(xref); |
| } |
| return wrapWithMessage(exception, msg); |
| } |
| |
| private static String see(final String entry) { |
| return FOR_MORE_DETAILS_SEE + HADOOP_WIKI + entry; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private static <T extends IOException> T wrapWithMessage( |
| T exception, String msg) { |
| Class<? extends Throwable> clazz = exception.getClass(); |
| try { |
| Constructor<? extends Throwable> ctor = |
| clazz.getConstructor(String.class); |
| Throwable t = ctor.newInstance(msg); |
| return (T) (t.initCause(exception)); |
| } catch (Throwable e) { |
| return exception; |
| } |
| } |
| |
| } |