/**
* 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 javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.net.*;
import java.security.PrivilegedExceptionAction;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.hdfs.DFSClient;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.conf.*;
public class StreamFile extends DfsServlet {
static InetSocketAddress nameNodeAddr;
static DataNode datanode = null;
static {
if ((datanode = DataNode.getDataNode()) != null) {
nameNodeAddr = datanode.getNameNodeAddr();
}
}
/** getting a client for connecting to dfs */
protected DFSClient getDFSClient(HttpServletRequest request)
throws IOException, InterruptedException {
Configuration conf =
(Configuration) getServletContext().getAttribute(JspHelper.CURRENT_CONF);
UserGroupInformation ugi = getUGI(request, conf);
return JspHelper.getDFSClient(ugi, nameNodeAddr, conf);
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String filename = request.getParameter("filename");
if (filename == null || filename.length() == 0) {
response.setContentType("text/plain");
PrintWriter out = response.getWriter();
out.print("Invalid input");
return;
}
DFSClient dfs;
try {
dfs = getDFSClient(request);
} catch (InterruptedException e) {
response.sendError(400, e.getMessage());
return;
}
FSInputStream in = dfs.open(filename);
OutputStream os = response.getOutputStream();
response.setHeader("Content-Disposition", "attachment; filename=\"" +
filename + "\"");
response.setContentType("application/octet-stream");
byte buf[] = new byte[4096];
try {
int bytesRead;
while ((bytesRead = in.read(buf)) != -1) {
os.write(buf, 0, bytesRead);
}
} finally {
in.close();
os.close();
dfs.close();
}
}
}