org.apache.hadoop.hdfs.server.namenode

Class GetImageServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.apache.hadoop.hdfs.server.namenode.GetImageServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

@InterfaceAudience.Private
public class GetImageServlet
extends javax.servlet.http.HttpServlet

This class is used in Namesystem's jetty to retrieve a file. Typically used by the Secondary NameNode to retrieve image and edit file for periodic checkpointing.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	CONTENT_DISPOSITION
static String	HADOOP_IMAGE_EDITS_HEADER

Constructor Summary

Constructors

Constructor and Description
GetImageServlet()

Method Summary

Methods

Modifier and Type	Method and Description
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
static DataTransferThrottler	getThrottler(Configuration conf) Construct a throttler from conf
static void	setFileNameHeaders(javax.servlet.http.HttpServletResponse response, File file)
static void	setVerificationHeaders(javax.servlet.http.HttpServletResponse response, File file) Set headers for content length, and, if available, md5.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CONTENT_DISPOSITION

public static final String CONTENT_DISPOSITION

See Also:

Constant Field Values

HADOOP_IMAGE_EDITS_HEADER

public static final String HADOOP_IMAGE_EDITS_HEADER

See Also:

Constant Field Values

Constructor Detail

GetImageServlet

public GetImageServlet()

Method Detail

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
         javax.servlet.http.HttpServletResponse response)
           throws javax.servlet.ServletException,
                  IOException

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

setFileNameHeaders

public static void setFileNameHeaders(javax.servlet.http.HttpServletResponse response,
                      File file)

getThrottler

public static final DataTransferThrottler getThrottler(Configuration conf)

Construct a throttler from conf

Parameters:

conf - configuration

Returns:

a data transfer throttler

setVerificationHeaders

public static void setVerificationHeaders(javax.servlet.http.HttpServletResponse response,
                          File file)
                                   throws IOException

Set headers for content length, and, if available, md5.

Throws:

IOException