Question

My java is a bit rusty, and I have to implement a solution for this problem.

Given in A.java where:

public class A implements Cloneable{
  protected DataStorage Y = new DataStorage();

  public A(DataStorage X, about 20 other inputs of different Object types){
   this.Y=X;
  }

  public static DataStorage getData(){
   return this.Y;
  }
}

My goal in another file ServletA.java where I want to retrieve the object Y or X. By doing a static call from A.java class… does it work or is there a better way?

public class ServletA{
  DataStorage Z = A.getData();
}

Note: Yes, this doesn’t compile, but is there a solution around it?

My constraints that I have for the solution:

• to make minimal changes to A.java because it is legacy codebase
• there are many 20+ inputs for the A() constructor which is a nightmare
• and my architect doesnt want to touch it either by changing A into an abstract class
• cannot create an instance of A in ServletA.java

EDIT1: my question is if there is a solution to access X from ServletA.java WITHOUT creating an instance of A in ServletA.java. The above code is an example to show that i have thought of a method, but it doesnt work.

EDIT 2: if you want to downvote, please ask me for clarifications as courtesy. thanks!

Answer 1

If you only have one instance of A you should use the singleton pattern.
Your ServletA code should be something like

public class ServletA {
  DataStorage Z = A.getInstance().getData();
}