java - Should Helper/Utility Classes be abstract?

Question

I commonly find myself extracting common behavior out of classes into helper/utility classes that contain nothing but a set of static methods. I've often wondered if I should be declaring these classes as abstract, since I can't really think of a valid reason to ever instantiate these?

What would the Pros and Cons be to declaring such a class as abstract.

public [abstract] class Utilities{

   public static String getSomeData(){
       return "someData";
   }

   public static void doSomethingToObject(Object arg0){
   }
}

Answer 1

You could just declare a private constructor that does nothing.

The problem with declaring the class "abstract" is that the abstract keyword usually means that class is intended to be subclassed and extended. That's definitely not what you want here.