Workaround to accessing non-static member method from a static inner class

Question

I have this non-static inner class that causes memory leaks, because it holds an implicit reference to the enclosing class:

private class CalendarScheduleUpdatedEventListener extends ScheduleUpdatedEventListener.Stub {

    @Override
    public void onScheduleUpdatedEvent() throws RemoteException {
        updateCalendar();
    }
}

In order to stop it from leaking, I need to make it static:

private static class CalendarScheduleUpdatedEventListener extends ScheduleUpdatedEventListener.Stub {

    @Override
    public void onScheduleUpdatedEvent() throws RemoteException {
        updateCalendar();-> Compiler error - trying to access a non-static...
    }
}

It is impossible to make updateCalendar() static because in it I access other non-static variables and it becomes a mess. What do I do?

Answer 1

You need to pass in a reference to an instance of your outer class. And you need to make your static class public.

public static class CalendarScheduleUpdatedEventListener extends ScheduleUpdatedEventListener.Stub {

    @Override
    public void onScheduleUpdatedEvent(final TheOuterClass instance) throws RemoteException {
        instance.updateCalendar();
    }
}

Answer 2

private static class CalendarScheduleUpdatedEventListener extends ScheduleUpdatedEventListener.Stub {
    final WeakReference<Object> obj; //change <Object> to whatever type it is.

    CalendarScheduleUpdatedEventListener(Object x) {
        this.obj = new WeakReference<>(x);
    }

    @Override
    public void onScheduleUpdatedEvent() throws RemoteException {
        Object o = obj.get();
        if (o == null) {
            //because a WeakReference will be null if it has been garbage collected.
            return; //or throw some exception
        }
        o.updateCalendar();
    }
}