Private constructor and inheritance (Java) -

i have first class constructor takes parameter.

public class first {     first(object o){         o.tostring();     } } 

i have second class extends first one.

public class second extends first {     second(object o) {         super(o);     } } 

what want keep constructor of second class private in order to have possibility instantiate 1 instance of class (using singleton pattern, instance), compiler doesn't allow me that.

if can't set constructor private here, can allow 1 instance of class created?

you can make constructor of second private no problems. can't make constructor of first private, unless use nested classes.

as example, works fine:

class first {     first(object o) {         o.tostring();     } }  class second extends first {     private final static second instance = new second(new object());      private second(object o) {         super(o);     }      public static second getinstance() {         return instance;     }     }