Hi, I have a spring boot project in which I’ve a Service (just a

class xyzService.kt

). In this service, i have several private values. Now, for the usecase I’m trying to solve in this service, I wanted to have an

abstract inner class Action

which has 1 more layer of inner classes, like

inner class Action.Cancel

,

Action.Start

etc (actual usecases are a bit more complex but I guess this translates okay). Each of these inner classes should also have access to the values in the top level service class. Then from the service class (but outside the Action class) I wish to be able to do

Action.Cancel().execute()

(execute is an overridden function from the superclass). However, I seem to run into some issues with these visibility modifiers. When attempting to interact with the values in the top level service class, I get the following:

Constructor of inner class Start can be called only with receiver of containing class

. Am I using the wrong hierarchy here? What’d be more appropriate? Does this seem like a wrong way to do things?

you have the same issue in java if you have something like

public class Outer {
  public class Inner {
  }
}

you cannot call

new Outer.Inner()

. if you want to use this syntax, inner must be

static

, otherwise you need to do

new Outer().Inner()

A better approach would be to extract that class hierarchy to another file. It would fix your problem and improve code readability and organization. Have in mind that naming would also change probably if that

Action

is specific for that particular service.

That would be difficult. The service class holds a few other services as values, and the Action class and subclasses hold feature-level logic from each of these services. A bit tightly coupled.