如何在java中将变量从一个Jframe（或类）传递到另一个？

I have looked at a couple of examples that would return values, but I don't fully understand how to make them work in my own code. I figured I should post it here and see if I can get some good pointers. I need to do a check to see if the user has logged in, then if they have logged in open the window to allow them to create the event(I can make the logic work with the if, then, and else statements). The part I need help with is passing the variables from the login class to the CreateEventActionPerformed . The following is from my mainFrame Jframe class: I have looked at a couple of examples that woul