Java SE (Java Platform, Standard Edition)

In my main controller class I have

public static final Stage fpStage =new Stage();


                    fpStage.setScene(scene);
                    fpStage.show();

okay in my secondary controller class I have

import particlesxml.MainwindowController;


this.okayButton.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent event)  {
              
              MainwindowController.fpStage.hide();
                
                
                
                
            }//end of handle
        }); //end of action event and set on action
        

This compiles just fine but does not work!!!. How do we close window2 brought up by java controller for window1, from java controller for window2.

fpStage for my project is the Stage (window) for Window2.