public String MD5( String str ) throws Exception
{
    MessageDigest md;

    md = MessageDigest.getInstance( "MD5" );
    md.reset();
    md.update( str.getBytes( "UTF-8" ) );
    byte[] digest = md.digest();

    BigInteger bigInt = new BigInteger( 1, digest );
    String hashtext = bigInt.toString( 16 );

    return hashtext;
}