Question

In my program, I’m making use of an ArrayList of ArrayList of booleans. I need these values carried from class to class and I’ve been doing so by simply making it static.

But I’m getting wind that this might be in bad taste. I was thinking that the best way to do without would be to make an object (a top-level one) with that collection as the central focus, probably with some methods to accompany this.

So my questions:

1. Is this better?
2. How do I keep one instance of the top-level object throughout the application so my values can transfer? I’m thinking a private constructor and static methods. Or should I just go with public fields? What is the approved method?

Answer 1

– If you don’t want to go with static ArrayList, then you can make a class Singleton and place that ArrayList into that class.

Eg:

public class Test{

  private ArrayList<String> arr = new ArrayList<String>();

  private static Test uniqueInstance = new Test();

  private Test{}      // Make constructor Private

  public static Test getInstance(){

    return uniqueInstance;


   }

}