StreamFile.java
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上传日期:2018-01-08
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文件大小:3k
- /**
- * 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 org.apache.hadoop.fs.*;
- import org.apache.hadoop.hdfs.DFSClient;
- import org.apache.hadoop.hdfs.server.datanode.DataNode;
- import org.apache.hadoop.security.UnixUserGroupInformation;
- import org.apache.hadoop.conf.*;
- public class StreamFile extends DfsServlet {
- static InetSocketAddress nameNodeAddr;
- static DataNode datanode = null;
- private static final Configuration masterConf = new Configuration();
- static {
- if ((datanode = DataNode.getDataNode()) != null) {
- nameNodeAddr = datanode.getNameNodeAddr();
- }
- }
-
- /** getting a client for connecting to dfs */
- protected DFSClient getDFSClient(HttpServletRequest request)
- throws IOException {
- Configuration conf = new Configuration(masterConf);
- UnixUserGroupInformation.saveToConf(conf,
- UnixUserGroupInformation.UGI_PROPERTY_NAME, getUGI(request));
- return new DFSClient(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 = getDFSClient(request);
- 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();
- }
- }
- }