| /** |
| * 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.hdfs.server.namenode; |
| |
| import java.io.IOException; |
| import java.net.InetSocketAddress; |
| |
| import javax.servlet.ServletContext; |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.http.HttpServletRequest; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hdfs.DFSUtil; |
| import org.apache.hadoop.hdfs.HdfsConfiguration; |
| import org.apache.hadoop.hdfs.protocol.ClientProtocol; |
| import org.apache.hadoop.hdfs.server.common.JspHelper; |
| import org.apache.hadoop.ipc.RemoteException; |
| import org.apache.hadoop.security.UserGroupInformation; |
| import org.znerd.xmlenc.XMLOutputter; |
| |
| /** |
| * A base class for the servlets in DFS. |
| */ |
| abstract class DfsServlet extends HttpServlet { |
| /** For java.io.Serializable */ |
| private static final long serialVersionUID = 1L; |
| |
| static final Log LOG = LogFactory.getLog(DfsServlet.class.getCanonicalName()); |
| |
| /** Write the object to XML format */ |
| protected void writeXml(Exception except, String path, XMLOutputter doc) |
| throws IOException { |
| doc.startTag(RemoteException.class.getSimpleName()); |
| doc.attribute("path", path); |
| if (except instanceof RemoteException) { |
| doc.attribute("class", ((RemoteException) except).getClassName()); |
| } else { |
| doc.attribute("class", except.getClass().getName()); |
| } |
| String msg = except.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 a {@link NameNode} proxy from the current {@link ServletContext}. |
| */ |
| protected ClientProtocol createNameNodeProxy() throws IOException { |
| ServletContext context = getServletContext(); |
| // if we are running in the Name Node, use it directly rather than via |
| // rpc |
| NameNode nn = NameNodeHttpServer.getNameNodeFromContext(context); |
| if (nn != null) { |
| return nn.getRpcServer(); |
| } |
| InetSocketAddress nnAddr = |
| NameNodeHttpServer.getNameNodeAddressFromContext(context); |
| Configuration conf = new HdfsConfiguration( |
| NameNodeHttpServer.getConfFromContext(context)); |
| return DFSUtil.createNamenode(nnAddr, conf); |
| } |
| |
| protected UserGroupInformation getUGI(HttpServletRequest request, |
| Configuration conf) throws IOException { |
| return JspHelper.getUGI(getServletContext(), request, conf); |
| } |
| } |