Package test

Class Checksum

java.lang.Object

test.Checksum

public final class Checksum
extends Object

Includes methods to generate the MD5 and SHA1 checksum.

Version:

$Id: $Id

Author:

Jeremy Long

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	Checksum.FileChecksums	File checksums for each supported algorithm

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	BUFFER_SIZE	Buffer size for calculating checksums.
private static final Map<File,Checksum.FileChecksums>	CHECKSUM_CACHE	Cached file checksums for each supported algorithm.
private static final String	HEXES	Hex code characters used in getHex.
private static final Logger	LOGGER	The logger.
private static final String	MD5	MD5 constant.
private static final String	SHA1	SHA1 constant.
private static final String	SHA256	SHA256 constant.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Checksum()	Private constructor for a utility class.

Method Summary

Modifier and Type	Method	Description
static String	getChecksum(String algorithm, byte[] bytes)	Calculates the MD5 checksum of a specified bytes.
static String	getChecksum(String algorithm, File file)	Creates the cryptographic checksum of a given file using the specified algorithm.
static String	getHex(byte[] raw)	Converts a byte array into a hex string.
static String	getMD5Checksum(File file)	Calculates the MD5 checksum of a specified file.
static String	getMD5Checksum(String text)	Calculates the MD5 checksum of the specified text.
private static MessageDigest	getMessageDigest(String algorithm)	Returns the message digest.
static String	getSHA1Checksum(File file)	Calculates the SHA1 checksum of a specified file.
static String	getSHA1Checksum(String text)	Calculates the SHA1 checksum of the specified text.
static String	getSHA256Checksum(File file)	Calculates the SH256 checksum of a specified file.
static String	getSHA256Checksum(String text)	Calculates the SHA256 checksum of the specified text.
private static byte[]	stringToBytes(String text)	Converts the given text into bytes.

Methods inherited from class java.lang.Object

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

Field Details

HEXES

private static final String HEXES

Hex code characters used in getHex.

See Also:

• Constant Field Values

BUFFER_SIZE

private static final int BUFFER_SIZE

Buffer size for calculating checksums.

See Also:

• Constant Field Values

LOGGER

private static final Logger LOGGER

The logger.

MD5

private static final String MD5

MD5 constant.

See Also:

• Constant Field Values

SHA1

private static final String SHA1

SHA1 constant.

See Also:

• Constant Field Values

SHA256

private static final String SHA256

SHA256 constant.

See Also:

• Constant Field Values

CHECKSUM_CACHE

private static final Map<File,Checksum.FileChecksums> CHECKSUM_CACHE

Cached file checksums for each supported algorithm.

Constructor Details

Checksum

private Checksum()

Private constructor for a utility class.

Method Details

getChecksum

public static String getChecksum(String algorithm,
 File file)
                          throws NoSuchAlgorithmException,
IOException

Creates the cryptographic checksum of a given file using the specified algorithm.

Parameters:

algorithm - the algorithm to use to calculate the checksum

file - the file to calculate the checksum for

Returns:

the checksum

Throws:

IOException - when the file does not exist

NoSuchAlgorithmException - when an algorithm is specified that does not exist

getMD5Checksum

public static String getMD5Checksum(File file)
                             throws IOException,
NoSuchAlgorithmException

Calculates the MD5 checksum of a specified file.

Parameters:

file - the file to generate the MD5 checksum

Returns:

the hex representation of the MD5 hash

Throws:

IOException - when the file passed in does not exist

NoSuchAlgorithmException - when the MD5 algorithm is not available

getSHA1Checksum

public static String getSHA1Checksum(File file)
                              throws IOException,
NoSuchAlgorithmException

Calculates the SHA1 checksum of a specified file.

Parameters:

file - the file to generate the MD5 checksum

Returns:

the hex representation of the SHA1 hash

Throws:

IOException - when the file passed in does not exist

NoSuchAlgorithmException - when the SHA1 algorithm is not available

getSHA256Checksum

public static String getSHA256Checksum(File file)
                                throws IOException,
NoSuchAlgorithmException

Calculates the SH256 checksum of a specified file.

Parameters:

file - the file to generate the MD5 checksum

Returns:

the hex representation of the SHA1 hash

Throws:

IOException - when the file passed in does not exist

NoSuchAlgorithmException - when the SHA1 algorithm is not available

getChecksum

public static String getChecksum(String algorithm,
 byte[] bytes)

Calculates the MD5 checksum of a specified bytes.

Parameters:

algorithm - the algorithm to use (md5, sha1, etc.) to calculate the message digest

bytes - the bytes to generate the MD5 checksum

Returns:

the hex representation of the MD5 hash

getMD5Checksum

public static String getMD5Checksum(String text)

Calculates the MD5 checksum of the specified text.

Parameters:

text - the text to generate the MD5 checksum

Returns:

the hex representation of the MD5

getSHA1Checksum

public static String getSHA1Checksum(String text)

Calculates the SHA1 checksum of the specified text.

Parameters:

text - the text to generate the SHA1 checksum

Returns:

the hex representation of the SHA1

getSHA256Checksum

public static String getSHA256Checksum(String text)

Calculates the SHA256 checksum of the specified text.

Parameters:

text - the text to generate the SHA1 checksum

Returns:

the hex representation of the SHA1

stringToBytes

private static byte[] stringToBytes(String text)

Converts the given text into bytes.

Parameters:

text - the text to convert

Returns:

the bytes

getHex

public static String getHex(byte[] raw)

Converts a byte array into a hex string.

This method was copied from http://www.rgagnon.com/javadetails/java-0596.html

Parameters:

raw - a byte array

Returns:

the hex representation of the byte array

getMessageDigest

private static MessageDigest getMessageDigest(String algorithm)

Returns the message digest.

Parameters:

algorithm - the algorithm for the message digest

Returns:

the message digest