Question

CASE STUDY: Calculate Salary at a University

There are two classes of employees at the university, namely Lecturers and Ordinary Staff.
All employees get the same starting salary, which is 1,500,000
Additional salaries for lecturers are calculated from the number of credits they can afford
Additional staff salaries are calculated from the number of attendances per month

Make class diagrams and programs with Java language to print all employee salaries

Answer 1

===========================

JAVA PROGRAM

===========================

///////////////////TestSalary.java//////////////////////////

import java.util.Scanner;

/*************

Test salary of employees

*************/

public class TestSalary {
  
   public static void main(String[] args){
      
       Scanner sc = new Scanner(System.in);
      
       System.out.println("Enter pay per credit for lecturer: ");
       double payPerCredit = sc.nextDouble(); //read value from user
      
       System.out.println("Enter pay per atttendance for ordinary staff: ");
       double payPerAttendance = sc.nextDouble(); //read value from user
      
       sc.close();
      
       //create instances and calculate salary
       Employee e1 = new Lecturer(50,payPerCredit);
       System.out.println("Salary for "+e1+ " is = "+e1.calculateSalary());
       Employee e2 = new Lecturer(37,payPerCredit);
       System.out.println("Salary for "+ e2 +" is = "+e2.calculateSalary());
       Employee e3 = new OrdinaryStaff(28,payPerAttendance);
       System.out.println("Salary for "+e3+ " is = "+e3.calculateSalary());
       Employee e4 = new OrdinaryStaff(25,payPerAttendance);
       System.out.println("Salary for "+e4+ " is = "+e4.calculateSalary());
  
      
   }

}

//////////////////////////////Employee.java//////////////////////////////

/**
* Employer :abstract class
*/
public abstract class Employee {
   //private field: starting salary
   private double startingSalary;
  
   public Employee(){
       this.startingSalary = 1500000; //set it up
   }
  
   //getter for stating salary
   public double getStartingSalary() {
       return startingSalary;
   }

   //abstract metho: to be implemented in derived classes
   public abstract double calculateSalary();
}

/////////////////////////////Lecturer.java//////////////////////////////////////

/**
*Class Lecturer derived from Employee class
*/
public class Lecturer extends Employee{
   //2 private fields
   private int numberOfCredits;
   private double payPerCredit;
  
   //constructor
   public Lecturer(int numberOfCredits,double payPerCredit) {
       super();
       this.numberOfCredits = numberOfCredits;
       this.payPerCredit = payPerCredit;
   }
   @Override
   public double calculateSalary() {
       //calculate total salary
       return (getStartingSalary() + (numberOfCredits * payPerCredit));
   }
   @Override
   public String toString() {
       return "Lecturer [numberOfCredits=" + numberOfCredits + ", payPerCredit=" + payPerCredit + "]";
   }

  
}

/////////////////////////////OrdinaryStaff.java////////////////////////////////////////

/**
*Class OrdinaryStaff derived from Employee class
*/
public class OrdinaryStaff extends Employee{
   //2 private fields
   private int attendancePerMonth;
   private double payPerAttendance;
  
   //constructor
   public OrdinaryStaff(int attendancePerMonth,double payPerAttendance) {
       super();
       this.attendancePerMonth = attendancePerMonth;
       this.payPerAttendance = payPerAttendance;
   }
   @Override
   public double calculateSalary() {
       //calculate total salary
       return (getStartingSalary() + (attendancePerMonth * payPerAttendance));
   }
   @Override
   public String toString() {
       return "OrdinaryStaff [attendancePerMonth=" + attendancePerMonth + ", payPerAttendance=" + payPerAttendance
               + "]";
   }
  
  

}

=======================================

OUTPUT

========================================

Enter pay per credit for lecturer:
375.75
Enter pay per atttendance for ordinary staff:
25.45
Salary for Lecturer [numberOfCredits=50, payPerCredit=375.75] is = 1518787.5
Salary for Lecturer [numberOfCredits=37, payPerCredit=375.75] is = 1513902.75
Salary for OrdinaryStaff [attendancePerMonth=28, payPerAttendance=25.45] is = 1500712.6
Salary for OrdinaryStaff [attendancePerMonth=25, payPerAttendance=25.45] is = 1500636.25