| /** |
| * 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.ipc; |
| |
| import java.io.IOException; |
| import java.lang.reflect.Constructor; |
| |
| import org.xml.sax.Attributes; |
| import org.znerd.xmlenc.XMLOutputter; |
| |
| public class RemoteException extends IOException { |
| /** For java.io.Serializable */ |
| private static final long serialVersionUID = 1L; |
| |
| private String className; |
| |
| public RemoteException(String className, String msg) { |
| super(msg); |
| this.className = className; |
| } |
| |
| public String getClassName() { |
| return className; |
| } |
| |
| /** |
| * If this remote exception wraps up one of the lookupTypes |
| * then return this exception. |
| * <p> |
| * Unwraps any IOException. |
| * |
| * @param lookupTypes the desired exception class. |
| * @return IOException, which is either the lookupClass exception or this. |
| */ |
| public IOException unwrapRemoteException(Class<?>... lookupTypes) { |
| if(lookupTypes == null) |
| return this; |
| for(Class<?> lookupClass : lookupTypes) { |
| if(!lookupClass.getName().equals(getClassName())) |
| continue; |
| try { |
| return instantiateException(lookupClass.asSubclass(IOException.class)); |
| } catch(Exception e) { |
| // cannot instantiate lookupClass, just return this |
| return this; |
| } |
| } |
| // wrapped up exception is not in lookupTypes, just return this |
| return this; |
| } |
| |
| /** |
| * Instantiate and return the exception wrapped up by this remote exception. |
| * |
| * <p> This unwraps any <code>Throwable</code> that has a constructor taking |
| * a <code>String</code> as a parameter. |
| * Otherwise it returns this. |
| * |
| * @return <code>Throwable |
| */ |
| public IOException unwrapRemoteException() { |
| try { |
| Class<?> realClass = Class.forName(getClassName()); |
| return instantiateException(realClass.asSubclass(IOException.class)); |
| } catch(Exception e) { |
| // cannot instantiate the original exception, just return this |
| } |
| return this; |
| } |
| |
| private IOException instantiateException(Class<? extends IOException> cls) |
| throws Exception { |
| Constructor<? extends IOException> cn = cls.getConstructor(String.class); |
| cn.setAccessible(true); |
| String firstLine = this.getMessage(); |
| int eol = firstLine.indexOf('\n'); |
| if (eol>=0) { |
| firstLine = firstLine.substring(0, eol); |
| } |
| IOException ex = cn.newInstance(firstLine); |
| ex.initCause(this); |
| return ex; |
| } |
| |
| /** Write the object to XML format */ |
| public void writeXml(String path, XMLOutputter doc) throws IOException { |
| doc.startTag(RemoteException.class.getSimpleName()); |
| doc.attribute("path", path); |
| doc.attribute("class", getClassName()); |
| String msg = getLocalizedMessage(); |
| int i = msg.indexOf("\n"); |
| if (i >= 0) { |
| msg = msg.substring(0, i); |
| } |
| doc.attribute("message", msg.substring(msg.indexOf(":") + 1).trim()); |
| doc.endTag(); |
| } |
| |
| /** Create RemoteException from attributes */ |
| public static RemoteException valueOf(Attributes attrs) { |
| return new RemoteException(attrs.getValue("class"), |
| attrs.getValue("message")); |
| } |
| } |