org.apache.hadoop.hdfs.util

Class MD5FileUtils

java.lang.Object

org.apache.hadoop.hdfs.util.MD5FileUtils

public abstract class MD5FileUtils
extends Object

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

Constructor Summary

Constructors

Constructor and Description
MD5FileUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static org.apache.hadoop.io.MD5Hash	computeMd5ForFile(File dataFile) Read dataFile and compute its MD5 checksum.
static File	getDigestFileForFile(File file)
static org.apache.hadoop.io.MD5Hash	readStoredMd5ForFile(File dataFile) Read the md5 checksum stored alongside the given file, or null if no md5 is stored.
static void	saveMD5File(File dataFile, org.apache.hadoop.io.MD5Hash digest) Save the ".md5" file that lists the md5sum of another file.
static void	verifySavedMD5(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

Constructor Detail

MD5FileUtils

public MD5FileUtils()

Method Detail

verifySavedMD5

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

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

Throws:

IOException

readStoredMd5ForFile

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

Read the md5 checksum stored alongside the given file, or null if no md5 is stored.

Parameters:

dataFile - the file containing data

Returns:

the checksum stored in dataFile.md5

Throws:

IOException

computeMd5ForFile

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

Read dataFile and compute its MD5 checksum.

Throws:

IOException

saveMD5File

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

IOException

getDigestFileForFile

public static File getDigestFileForFile(File file)

Returns:

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