Applet servlet communication

Hi,
Due to the size of my file on server/nearly 80MB/, I am now compelled to consider server processing. Becoz the applet is not able to process this much amount of file on the browser side.

My task is generating a Graphics to be displayed on applet, from text files. Before generating the graphics, the program should compare, add/subtract ... the contents of the files/all files are double type 102X102 number matrices/.

Please suggest me which applet - server communication option is better, in terms of easiness and reliability.
1. Applet -servlet ?
2. Applet - server using socket ?

I have done some coding/which doesn't file processing/, on applet forms. Now I want a server side program to process everything/based on user preferences on the applet/, and send a finished graphics image to the applet.
Thanks in advance.