How to run executable Java app from command line: No Main( ) method

Question

This is the opposite question from what most users ask. I have the Java source code and a running Java executable version of the program in a windows environment. I don't want to run it in the normal way by double-clicking on it or using the executable. I need to be able to run the same application from the command line. If I can do this, I can then compile and run the code on my Mac, too, which is what I am ultimately trying to accomplish.
Normally, this would be easy. I would look for a Main method, normally public static void main (String[] args ) or some variation. I cannot find a main() anything, anywhere when searching the files. There must be some windows executable that links to the Java classes. It's very clever, no doubt, but that's not helping me.
I am trying to run what I can determine as the Main class, with a standard command line call, but that is not working either.
It is a Java graphics program, so mostly Swing container stuff.
I am not finding a manifest.txt file, telling me where a main method is, nor anything about the Main Class. There is no readme file for the program.
Any insight that would point me in the right direction? What should I be looking for?
Thanks in advance, Bloozman

Answer 1

It's possible there's a clever Windows executable that runs the class. But if it's a plain old Java class then there's a good chance there's a constructor. Look for that; it's possible you may be able to start by writing another Java class that creates an instance of your mystery class.
When you have that done, try running it. It's possible that just creating an instance might be sufficient to run it. Swing programs are sometimes written like that. If not, then start looking for methods with names like "run" or "go" or "start" that your little controller program can call.