Welcome to the Ranch
What happens is you set up a user name "jdoe" number "1234", etc. (line 13-25) and Strings with the date in eg "2011-05-14T12:34:56GMT" or something similar (line 26-35).
Then it seems to divide the whole lot into an array of bytes, changes each byte into hexadecimal format, joins them all up with a StringBuilder (line 40-64), and uses that information to make a log in (line 69 to 76). Note the information put into the StringBuilder appears to have been changed into its SHA256 form. That is not true encryption, because you can turn a String into an SHA256 but you can't turn the SHA256 back into the String.
I don't think it actually logs on, but it displays what the URL would be if you did log on. At the next stage in development, I presume you would use that URL in real life.
If you require more details, please ask again.