Use Java to implement the MD5 Algorithm

Found on a foreigner's website! Modified it!

 

Import java. Security. messagedigest;
Public class MD5
...{
Private messagedigest MD5;
Private Static MD5 instance;

/***//**
* Constructs the MD5 object and sets the string whose MD5 is to be computed.
*
* @ Param instr the <code> string </code> whose MD5 is to be computed
*/
Public synchronized static MD5 getmd5instance ()
...{
If (instance = NULL)
Instance = new MD5 ();
Return instance;
}
Private MD5 ()
...{
Try ...{

This. MD5 = messagedigest. getinstance ("MD5 ");
}
Catch (exception E)
...{
System. Out. println (E. tostring ());
E. printstacktrace ();
}
}

/***//**
* Computes the MD5 fingerprint of a string.
*
* @ Return the MD5 Digest of the input <code> string </code>
*/
Public String compute (string instr)
...{
// Convert input string to a char []
// Convert that char [] to byte []
// Get the MD5 Digest as byte []
// Bit-wise and that byte [] with 0xff
// Prepend "0" to the output stringbuffer to make sure that we don't end up
// Something like "e21ff" instead of "e201ff"

Char [] chararray = instr. tochararray ();
Byte [] bytearray = new byte [chararray. Length];

For (INT I = 0; I <chararray. length; I ++)
Bytearray [I] = (byte) chararray [I];

Byte [] md5bytes = This. md5.digest (bytearray );

Stringbuffer hexvalue = new stringbuffer ();

For (INT I = 0; I <md5bytes. length; I ++)
...{
Int val = (INT) md5bytes [I]) & 0xff;
If (Val <16) hexvalue. append ("0 ");
Hexvalue. append (integer. tohexstring (VAL ));
}

Return hexvalue. tostring ();
}
Public static void main (string [] ARGs)
...{
System. Out. println (md5.getmd5instance (). Compute (""). touppercase ());
}
}