/**
* 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 org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.HftpFileSystem;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.DirectoryListing;
import org.apache.hadoop.hdfs.server.common.JspHelper;
import org.apache.hadoop.util.ServletUtil;
import org.apache.hadoop.util.VersionInfo;
import org.znerd.xmlenc.*;
import java.io.IOException;
import java.io.PrintWriter;
import java.security.PrivilegedExceptionAction;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Stack;
import java.util.regex.Pattern;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Obtain meta-information about a filesystem.
* @see org.apache.hadoop.hdfs.HftpFileSystem
*/
@InterfaceAudience.Private
public class ListPathsServlet extends DfsServlet {
/** For java.io.Serializable */
private static final long serialVersionUID = 1L;
public static final ThreadLocal<SimpleDateFormat> df =
new ThreadLocal<SimpleDateFormat>() {
protected SimpleDateFormat initialValue() {
return HftpFileSystem.getDateFormat();
}
};
/**
* Write a node to output.
* Node information includes path, modification, permission, owner and group.
* For files, it also includes size, replication and block-size.
*/
static void writeInfo(final Path fullpath, final HdfsFileStatus i,
final XMLOutputter doc) throws IOException {
final SimpleDateFormat ldf = df.get();
doc.startTag(i.isDir() ? "directory" : "file");
doc.attribute("path", fullpath.toUri().getPath());
doc.attribute("modified", ldf.format(new Date(i.getModificationTime())));
doc.attribute("accesstime", ldf.format(new Date(i.getAccessTime())));
if (!i.isDir()) {
doc.attribute("size", String.valueOf(i.getLen()));
doc.attribute("replication", String.valueOf(i.getReplication()));
doc.attribute("blocksize", String.valueOf(i.getBlockSize()));
}
doc.attribute("permission", (i.isDir()? "d": "-") + i.getPermission());
doc.attribute("owner", i.getOwner());
doc.attribute("group", i.getGroup());
doc.endTag();
}
/**
* Build a map from the query string, setting values and defaults.
*/
protected Map<String,String> buildRoot(HttpServletRequest request,
XMLOutputter doc) {
final String path = ServletUtil.getDecodedPath(request, "/listPaths");
final String exclude = request.getParameter("exclude") != null
? request.getParameter("exclude") : "";
final String filter = request.getParameter("filter") != null
? request.getParameter("filter") : ".*";
final boolean recur = request.getParameter("recursive") != null
&& "yes".equals(request.getParameter("recursive"));
Map<String, String> root = new HashMap<String, String>();
root.put("path", path);
root.put("recursive", recur ? "yes" : "no");
root.put("filter", filter);
root.put("exclude", exclude);
root.put("time", df.get().format(new Date()));
root.put("version", VersionInfo.getVersion());
return root;
}
/**
* Service a GET request as described below.
* Request:
* {@code
* GET http://<nn>:<port>/listPaths[/<path>][<?option>[&option]*] HTTP/1.1
* }
*
* Where <i>option</i> (default) in:
* recursive ("no")
* filter (".*")
* exclude ("\..*\.crc")
*
* Response: A flat list of files/directories in the following format:
* {@code
* <listing path="..." recursive="(yes|no)" filter="..."
* time="yyyy-MM-dd hh:mm:ss UTC" version="...">
* <directory path="..." modified="yyyy-MM-dd hh:mm:ss"/>
* <file path="..." modified="yyyy-MM-dd'T'hh:mm:ssZ" accesstime="yyyy-MM-dd'T'hh:mm:ssZ"
* blocksize="..."
* replication="..." size="..."/>
* </listing>
* }
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
final PrintWriter out = response.getWriter();
final XMLOutputter doc = new XMLOutputter(out, "UTF-8");
final Map<String, String> root = buildRoot(request, doc);
final String path = root.get("path");
final String filePath = ServletUtil.getDecodedPath(request, "/listPaths");
try {
final boolean recur = "yes".equals(root.get("recursive"));
final Pattern filter = Pattern.compile(root.get("filter"));
final Pattern exclude = Pattern.compile(root.get("exclude"));
final Configuration conf =
(Configuration) getServletContext().getAttribute(JspHelper.CURRENT_CONF);
getUGI(request, conf).doAs(new PrivilegedExceptionAction<Void>() {
@Override
public Void run() throws IOException {
ClientProtocol nn = createNameNodeProxy();
doc.declaration();
doc.startTag("listing");
for (Map.Entry<String, String> m : root.entrySet()) {
doc.attribute(m.getKey(), m.getValue());
}
HdfsFileStatus base = nn.getFileInfo(filePath);
if ((base != null) && base.isDir()) {
writeInfo(base.getFullPath(new Path(path)), base, doc);
}
Stack<String> pathstack = new Stack<String>();
pathstack.push(path);
while (!pathstack.empty()) {
String p = pathstack.pop();
try {
byte[] lastReturnedName = HdfsFileStatus.EMPTY_NAME;
DirectoryListing thisListing;
do {
assert lastReturnedName != null;
thisListing = nn.getListing(p, lastReturnedName, false);
if (thisListing == null) {
if (lastReturnedName.length == 0) {
LOG
.warn("ListPathsServlet - Path " + p
+ " does not exist");
}
break;
}
HdfsFileStatus[] listing = thisListing.getPartialListing();
for (HdfsFileStatus i : listing) {
final Path fullpath = i.getFullPath(new Path(p));
final String localName = fullpath.getName();
if (exclude.matcher(localName).matches()
|| !filter.matcher(localName).matches()) {
continue;
}
if (recur && i.isDir()) {
pathstack.push(new Path(p, localName).toUri().getPath());
}
writeInfo(fullpath, i, doc);
}
lastReturnedName = thisListing.getLastName();
} while (thisListing.hasMore());
} catch (IOException re) {
writeXml(re, p, doc);
}
}
return null;
}
});
} catch(IOException ioe) {
writeXml(ioe, path, doc);
} catch (InterruptedException e) {
LOG.warn("ListPathServlet encountered InterruptedException", e);
response.sendError(400, e.getMessage());
} finally {
if (doc != null) {
doc.endDocument();
}
if (out != null) {
out.close();
}
}
}
}