Package org.apache.hadoop.hdfs.util

Class MD5FileUtils

java.lang.Object

org.apache.hadoop.hdfs.util.MD5FileUtils

public abstract class MD5FileUtils
extends java.lang.Object

Static functions for dealing with files of the same format that the Unix "md5sum" utility writes.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	MD5_SUFFIX

Constructor Summary

Constructors

Constructor	Description
MD5FileUtils()

Method Summary

Modifier and Type	Method	Description
static org.apache.hadoop.io.MD5Hash	computeMd5ForFile(java.io.File dataFile)	Read dataFile and compute its MD5 checksum.
static java.io.File	getDigestFileForFile(java.io.File file)
static org.apache.hadoop.io.MD5Hash	readStoredMd5ForFile(java.io.File dataFile)	Read the md5 checksum stored alongside the given data file.
static void	renameMD5File(java.io.File oldDataFile, java.io.File newDataFile)
static void	saveMD5File(java.io.File dataFile, org.apache.hadoop.io.MD5Hash digest)	Save the ".md5" file that lists the md5sum of another file.
static void	verifySavedMD5(java.io.File dataFile, org.apache.hadoop.io.MD5Hash expectedMD5)	Verify that the previously saved md5 for the given file matches expectedMd5.

Methods inherited from class java.lang.Object

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

Field Detail

MD5_SUFFIX

public static final java.lang.String MD5_SUFFIX

See Also:

Constant Field Values

Constructor Detail

MD5FileUtils

public MD5FileUtils()

Method Detail

verifySavedMD5

public static void verifySavedMD5(java.io.File dataFile,
                                  org.apache.hadoop.io.MD5Hash expectedMD5)
                           throws java.io.IOException

Verify that the previously saved md5 for the given file matches expectedMd5.

Throws:

java.io.IOException

readStoredMd5ForFile

public static org.apache.hadoop.io.MD5Hash readStoredMd5ForFile(java.io.File dataFile)
                                                         throws java.io.IOException

Read the md5 checksum stored alongside the given data file.

Parameters:

dataFile - the file containing data

Returns:

the checksum stored in dataFile.md5

Throws:

java.io.IOException

computeMd5ForFile

public static org.apache.hadoop.io.MD5Hash computeMd5ForFile(java.io.File dataFile)
                                                      throws java.io.IOException

Read dataFile and compute its MD5 checksum.

Throws:

java.io.IOException

saveMD5File

public static void saveMD5File(java.io.File dataFile,
                               org.apache.hadoop.io.MD5Hash digest)
                        throws java.io.IOException

Save the ".md5" file that lists the md5sum of another file.

Parameters:

dataFile - the original file whose md5 was computed

digest - the computed digest

Throws:

java.io.IOException

renameMD5File

public static void renameMD5File(java.io.File oldDataFile,
                                 java.io.File newDataFile)
                          throws java.io.IOException

Throws:

java.io.IOException

getDigestFileForFile

public static java.io.File getDigestFileForFile(java.io.File file)

Returns:

a reference to the file with .md5 suffix that will contain the md5 checksum for the given data file.