Question

In the Employee class, add an implementation for the calculatePension() method
declared in the interface. Calculate the pension to date as the equivalent of a monthly
salary for every year in service.
4) Print the calculated pension for all employees.

************** I added the interface and I implemented the interface with Employee class but, I don't know how can i call the method in main class ************

import java.io.*;

public class ManagerTest
{ public static void main(String[] args)
{
InputStreamReader isr = null; //
BufferedReader br = null;

Employee[] staff = new Employee[3];

staff[0] = new Employee("Harry Hacker", 35000,
new Day(1989,10,1));
staff[1] = new Manager("Carl Cracker", 75000,
new Day(1987,12,15));
staff[2] = new Employee("Tony Tester", 38000,
new Day(1990,3,15));
int i;
for (i = 0; i < 3; i++) staff[i].raiseSalary(5);
for (i = 0; i < 3; i++) staff[i].print();
System.out.println("The PensionScheme for all Employee are: ");

}
}

class Employee implements PensionScheme
{ public Employee(String n, double s, Day d)
{ name = n;
salary = s;
hireDay = d;
}
public void print()
{ System.out.println(name + " " + salary + " "
+ hireYear());
}
public void raiseSalary(double byPercent)
{ salary *= 1 + byPercent / 100; //assume myPrecent=5. salary * 5 / 100
}
public int hireYear()
{ return hireDay.getYear();
}
@Override
public double calculatePension()
{
Day today = new Day();
double Pension = (today.getYear() - hireYear())*salary;
return Pension;
}
private String name;
private double salary;
private Day hireDay;
}

class Manager extends Employee
{ public Manager(String n, double s, Day d)
{ super(n, s, d);
secretaryName = "";
}

public void raiseSalary(double byPercent)
{ // add 1/2% bonus for every year of service
Day today = new Day();
double bonus = 0.5 * (today.getYear() - hireYear());
super.raiseSalary(byPercent + bonus);
}

public void setSecretaryName(String n)
{ secretaryName = n;
}

public String getSecretaryName()
{ return secretaryName;
}

private String secretaryName;
}

Answer 1

import java.io.*;

interface PensionScheme
{
public double calculatePension();
}
class ManagerTest
{ public static void main(String[] args)
   {
      InputStreamReader isr = null; //
      BufferedReader br = null;
      Employee[] staff = new Employee[3];
      staff[0] = new Employee("Harry Hacker", 35000,
         new Day(1989,10,1));
      staff[1] = new Manager("Carl Cracker", 75000,
         new Day(1987,12,15));
      staff[2] = new Employee("Tony Tester", 38000,
         new Day(1990,3,15));
      int i;
      for (i = 0; i < 3; i++) staff[i].raiseSalary(5);
      for (i = 0; i < 3; i++) staff[i].print();
      System.out.println("The monthly PensionScheme for all Employee are: ");
     for (i = 0; i < 3; i++) System.out.println(staff[i].calculatePension());
   }
}

class Day
{
private int day;
private int month;
private int year;

public Day()
{
day = 0;
month = 0;
year = 0;
}
public Day(int year,int month,int day)
{
this.day = day;
this.month = month;
this.year = year;
}

public int getDay()
{
return day;
}
public int getMonth()
{
return month;
}
public int getYear()
{
return year;
}
}
class Employee implements PensionScheme
{
public Employee(String n, double s, Day d)
   { name = n;
      salary = s;
      hireDay = d;
   }
   public void print()
   { System.out.println(name + " " + salary + " "
         + hireYear());
   }
   public void raiseSalary(double byPercent)
   { salary *= 1 + byPercent / 100; //assume myPrecent=5. salary * 5 / 100
   }
   public int hireYear()
   { return hireDay.getYear();
   }
   @Override
   public double calculatePension()
   {
       Day today = new Day();
       double Pension = (2018 - hireYear())*salary;// difference of hiring year and 2018
       return Pension/12;
   }
   private String name;
   private double salary;
   private Day hireDay;
}
class Manager extends Employee
{ public Manager(String n, double s, Day d)
   { super(n, s, d);
      secretaryName = "";
   }
   public void raiseSalary(double byPercent)
   { // add 1/2% bonus for every year of service
      Day today = new Day();
      double bonus = 0.5 * (2018 - hireYear());
      super.raiseSalary(byPercent + bonus);
   }
  
   public void setSecretaryName(String n)
   { secretaryName = n;
   }
   public String getSecretaryName()
   { return secretaryName;
   }
  
   private String secretaryName;
}

output:

Harry Hacker 36750.0 1989
Carl Cracker 90375.0 1987
Tony Tester 39900.0 1990
The monthly PensionScheme for all Employee are:
88812.5
233468.75
93100.0