Ftp Program - Updater In Java

[FelonBIG]

Hey guys!

 

Name's Evan, im currently studying in AUEB , in the computer science department.

 

So, a teacher gave me an assigment to create a simple updater program in java.

I would like to discuss with you, which is, in your opinion the best algorithm to use.

 

I have a beta version of the program ready.

 

It includes :

• Basic ftp utilities (download file, delete file , upload file , etc)
• A basic login panel , which uses text files as a database(the passwords are decoded and encoded with Ceaser cipher's method)

I wont keep it that way its just for test purposes

 

As for the update part, i thought about it like this :

 

1)Split the file on the server and the file in the local working directory into parts

2)Check each part seperately  (byte by byte) 

3)Keep track of the parts that changed

4)Delete the changed parts in the server, upload the updated ones and join the file back together

 

The problem is :

 

I have no permission to split/join the file in the ftp server....

Or at least i havent found a way yet...

So im trying to find a fast way to proccess the update, without having to download the file from the server in order to check it...

 

Thanks for your time.

Waiting for your opinion 

[drake2wow]

You can't access the bytes of a file till you download it, the FTP is gonna provide you only with a link and filename, in order to access the bytes you must download the file first and that will make your updater really really bad cause it will be dumb.

 

Play with MD5 hashes of the two files

[FelonBIG]

Thanks for the answer bro! Gonna test it and see what happens