written the server
written the client
found someone to buy them
how do i keep him from reading my code?
i have read stuff about obfuscation and A-O-T compilers
also, if possible, i would like to have both the server and client not use a locally installed JVM
(didnt know where to post it, so offtopic seemed the most appropriate one)
thank you
obfuscation can make it a little harder to decompile and read your code but its unlikely going to stop people stealing your super secret code algorithms.
Judging by your question, you might want to have a look at Excelsior Jet, its probably the best java AOT compiler and won’t require the client machine to have a JVM installed.
yeap, i read about obfuscators
and AOT compilers (Excelsior included)
the problem with excelsior is that i have to buy it
(and i am not so sure that it makes it so its not necessary for the client to have the Java runtime environments installed)
isnt there a free open source similar project?
( i am looking and i will post here if i find one)
and what about the gnu compiler? can i use it?
GNU compiler = shit. If you don’t mind selling shit, then this is fine.
If this software is actually worth any money, buy Jet.
If this software is not actually worth any money, then it’s worthless, so who cares if it’s protected or not.
Cas 
thank you for your brutal honesty
your logic does seem to stand on the side of righteousness
what if its worth little money, about a month’s beer money (though i do drink a lot) and i really need it? (still a student)
so i should make my app into a jar wrapped by an exe (saw that option in a software) and then explain why (and possibly how) to install JRE
edit:
question : does anyone know (or can guess) how the trial version works?
i mean, if i get a trial version of a painting software, after 30 days it will stop functioning, however my images saved in jpeg and png format will stay forever on my computer
if i download the trial version of such a program (i am considering Jar2Exe), will the exe generated keep working after the trial period? (have sent them an email, but i am not so sure they will answer)
While the GNU compiler is on the crappy side… it does have one feature… it is free
There is a simple GUI wrapper for the compiler that i have used in the past called Java Native Compiler (which is share ware and all exes will say that it has been made with a demo version) http://jnc.mtsystems.ch/
It was sufficient for my needs at the time. perhaps it will be sufficient for yours?
Is there something like http://upx.sourceforge.net/ for Java?
I know it won’t protect it too much but it would add that extra layer that would keep people like me from trying heh.
Then obfuscate:
thank you all for the info and opinions
edit: in case someone is interested i will post my decision and the (hopefully good) impression of the buyer of my program
I would definitely be interested in reading this.