Im writing a java system for some one, and no contract has been established so far.
Im just wondering, if i dont sign any contract, to whom does the source code of my project belong to?
Is it mine? do i sell it to him? does he just get it? how does that work?
other possibilities: whose machine did you write it on, are you using code/libraries from him (or another third partie), is this for your work, for a potential employer, for a course you're taking, .. ?
"Im writing a java system for some one, and no contract has been established so far."
you are contradicting yourself. you are writing an application for someone, which means: someone asked you to do so, and you agreed. <- that asking and agreeing might be considered a contract. it may be more difficult to prove. I'm just basing myself on our legal system here( not knowing where you are from and where your client/employer is from ).
is there a compensation of some sort agreed on upon completion of the project?
there's a lot you must consider before you can truly answer that question.
Find out what you are being paid for;
1. To code on their equipment (by the hour) - Source belongs to the client
2. Deliver an executable (*.class files) - Source belongs to you
3. Deliver source code (*.java files) - Source belongs to the client
Of course, there is nothing stopping you from taking a copy of the code for yourself.
However, you MUST modify it to perform a little differently, to call it yours.
I do it all of the time.
I take the code that I write for my clients and make it more efficient, easier to use, and more generic (reusable).