/**
* 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.io.PrintWriter;
import java.net.URI;
import java.net.URISyntaxException;
import java.security.PrivilegedExceptionAction;
import javax.net.SocketFactory;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.MD5MD5CRC32FileChecksum;
import org.apache.hadoop.hdfs.DFSClient;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.DatanodeID;
import org.apache.hadoop.hdfs.protocol.FSConstants;
import org.apache.hadoop.hdfs.server.common.HdfsConstants;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.UserGroupInformation;
import org.znerd.xmlenc.XMLOutputter;
/** Servlets for file checksum */
public class FileChecksumServlets {
/** Redirect file checksum queries to an appropriate datanode. */
public static class RedirectServlet extends DfsServlet {
/** For java.io.Serializable */
private static final long serialVersionUID = 1L;
/** {@inheritDoc} */
public void doGet(HttpServletRequest request, HttpServletResponse response
) throws ServletException, IOException {
final ServletContext context = getServletContext();
Configuration conf = (Configuration) context.getAttribute(JspHelper.CURRENT_CONF);
final UserGroupInformation ugi = getUGI(request, conf);
String tokenString = request.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
final NameNode namenode = (NameNode)context.getAttribute("name.node");
final DatanodeID datanode = namenode.getNamesystem().getRandomDatanode();
try {
final URI uri =
createRedirectUri("/getFileChecksum", ugi, datanode, request, tokenString);
response.sendRedirect(uri.toURL().toString());
} catch(URISyntaxException e) {
throw new ServletException(e);
//response.getWriter().println(e.toString());
} catch (IOException e) {
response.sendError(400, e.getMessage());
}
}
}
/** Get FileChecksum */
public static class GetServlet extends DfsServlet {
/** For java.io.Serializable */
private static final long serialVersionUID = 1L;
/** {@inheritDoc} */
public void doGet(HttpServletRequest request, HttpServletResponse response
) throws ServletException, IOException {
final PrintWriter out = response.getWriter();
final String filename = getFilename(request, response);
final XMLOutputter xml = new XMLOutputter(out, "UTF-8");
xml.declaration();
final Configuration conf = new Configuration(DataNode.getDataNode().getConf());
final int socketTimeout = conf.getInt("dfs.socket.timeout", HdfsConstants.READ_TIMEOUT);
final SocketFactory socketFactory = NetUtils.getSocketFactory(conf, ClientProtocol.class);
try {
ClientProtocol nnproxy = getUGI(request, conf).doAs
(new PrivilegedExceptionAction<ClientProtocol>() {
@Override
public ClientProtocol run() throws IOException {
return DFSClient.createNamenode(conf);
}
});
final MD5MD5CRC32FileChecksum checksum = DFSClient.getFileChecksum(
filename, nnproxy, socketFactory, socketTimeout);
MD5MD5CRC32FileChecksum.write(xml, checksum);
} catch(IOException ioe) {
writeXml(ioe, filename, xml);
} catch (InterruptedException e) {
writeXml(e, filename, xml);
}
xml.endDocument();
}
}
}