Question

I am working on a projects and I have run into a problem, I don’t know the best way to share updated data between classes. The current way that I am doing this is by having a static instance of my class in it and having all the other classes change the instance and not the original class.

public class A{
  public static volatile instance;
  public B b = new B();
  public C c = new C();
  public D d = new D();
  public A(){
  this.instance = this;
  b.changeData();
  }
}

public class B{
  public void changeData(){
  A.instance.d.changeSomethingInD();
  }
}

Now, all the changes that D made to its variables can be accessed by B and C. Is there a better way to do this?

Edit 1: The problem that I have is having updated variables accessible to all the other classes. This was what I was doing before:

public class MainClass extends JavaPlugin{
  private RegionLoader rLoader;
  private ClassesLoader cLoader;
  private MessageHandler mHandler;
  private PlayerDates pDates;

  public MainClass(){

      dirMaker();

      mHandler = new MessageHandler(this);
      pDates = new PlayerDates(this);
      cLoader = new ClassesLoader(this);
      rLoader = new RegionLoader(this);

  }
//getters and setters
}

But the problem is if the RegionLoader changes somithing within itself, the ClassesLoader won’t have the updated variables and will work with the old ones, or would it?

Answer 1

Why not just pass A into the constructor of B. This way you wouldn’t need to use static data.

   public class A{

      public B b;
      public C c = new C();
      public D d = new D();

      public A(){
         b = new B(this);
         b.changeData();
      }
    }

    public class B{
      private A a;

      public B(A a){
         this.a = a;
      }
      public void changeData(){
         a.d.changeSomethingInD();
      }
    }

You could also checkout the observer pattern.