Apologies for the generic nature of this question.

I have been learning Java for a few months now, and I've created a few simple projects which have some functionality. I wanted to send the projects to a friend and I'm running into countless errors and struggles. Passing a .jar file is causing "Main class not found" errors when they try to open it.

I tried using third party software to wrap the .jar files into an .exe file and the same errors still persist.

Beyond that, I'm convinced that passing around .jar files wrapped into .exe files via third party software is NOT how Java was intended to be used. I've read two books on Java and they all talk about structuring the language, but I'm confused about WHERE I'm supposed to be using this code because it has become painfully obvious that it is NOT intended to be passed around in file format.

Is this a server programming language? Used on the back end of websites mainly? I'm not sure where one would be using the code written in Java.