Question

I’m trying to launch a JavaFx application from within a JavaFx application, but it looks like Application.launch() can only be called once. Does this mean I have to start a separate JVM… as in exec(“java… or is there another way?

More background info. I want my JavaFx app to be able to build and run JavaFx apps. Right now it compiles classes in-memory, loads the classes… it would be really unfortunate to have to resort to writing everything to the filesystem so I can get a jar on the filesystem, so I can use exec to start it up.

As a secondary question… Is there a way to open another JavaFx window and get the stage and pass it to my newly compiled and loaded Application sub-class?

Answer 1

If you want to execute another JavaFX application in the same JVM you can just create instance of it, manually create Stage and call Application#start()

public void runAnotherApp(Class<? extends Application> anotherAppClass) throws Exception {
    Application app2 = anotherAppClass.newInstance(); 
    Stage anotherStage = new Stage();
    app2.start(anotherStage);
}

N.B.: it wouldn’t work if you use special features of standard initialization in anotherApp, e.g. Application.init() or Application.getParameters()