title: singleton and inheritance in Java
body: <p>I have a base class that captures some functionality common to two classes. In other words, I can create one base class and make these two classes subclasses of that base class. However, for each of these sub classes, the number of instances can be created is 1 (i.e. each sub class has to be a singleton).
  I googled and found that there's a reasonable debate going on over this. Although there are several solutions available, I am not sure whether they would fit in my case.</p>
  
  <p>can anyone tell me how I should design this?</p>