Splitting program into multiple files

Question

Hi folks :)
I have a looong program. And I would like to split it into 4 files. What else do I have to do, then adding the packagename? Could I call variables from one file, that is declared in another? How? And how do i call methods in another file?

Answer 1

Presumably, you're using Strings and possibly even JTextPanes.
If so, you already have all the syntax you need.
Let's assume that your current class contains all the required functionality. You might want to break that up to make the code more maintainable. So, put all the gui code into GUI.java and then wrap up your data processing methods into a Processor.java file. Both of these should define publilc classes.
But now your GUI class presumably won't compile because you are trying to call methods that don't exist anymore (you've just moved them). So, in you GUI class add a Processor data member (called "dataProcessor"). Instantiate this in the GUI constructor. Now, where you were calling those methods before you need to use:
dataProcessor.someMethod(someString);You'll probably have to play around a little to make everything fit but the art of refactoring is one to be learned early.
I hope this gives you the idea you were looking for.