public interface SalaryBusiness {

    double getSalary();
}

public class SalaryCalculator implements SalaryBusiness {

// Some shared fileds, useful for the calculation....

// A public constructor
 public SalaryCalculator()
{
}

protected SalaryCalculator(Object anObject)
{

// the anObject is useful to init the shared fileds
initFields(anObject)
}
//Method that creat a Regime
public final SalaryCalculator getRegimeCalculator(Object anObject)
{
if (newRegimeCalculator.equals(anObject.getRegime))
{
return new newRegimeCalculator(anObject);
}else {

NewRegimeCalculator newRegimeCalcultor = new NewRegimeCalculator(anObject);
OldRegimeCalculator oldRegimeCalculator = new OldRegimeCalculator(anObject);
oldRegimeCalculator.setTauxNr = newRegime.getSalary();
return oldRegimeCalculator
}

@override
public double getSalary()
{
return 0.0d;
}

}

public class NewRegimeCalculator extends SalaryCalculator {

       // Special fileds...

       // Procted constructor
       proctected NewRegimeCalculator(Object anObject) {
       super(anObject);
    }

    @override
    public double getSalary()
    {
    double salary = 0.0d;
      //Traitements....
     return salary;
    }
}



public class OldRegimeCalculator extends SalaryCalculator {

       // Field holding the newRegime salary
       double tauxNr = 0.0d;
       // Special fileds...

       // Procted constructor
       proctected OldRegimeCalculator(Object anObject) {
       super(anObject);
    }

    @override
    public double getSalary()
    {
    double salary = 0.0d;
      //Traitements....
     if (tauxNr>salary)
     {
return tauxNr;
}
else {
return salary;
}
    }

public classWantToGetTheSalary {

Object anObject;
double salary;
   SalaryCalculator regimeCalculator = new SalaryCalculator().getRegimeCalculator(anObject);

//Here is our salary
salary = regimeCalculator.getSalary();


}