Question

Hello i am working on a project for my programming course and i am a little lost. The assignment is as follows:

Part A

Do all of problem 3.13 (Employee Class), including the main, as written.

Part B

Now, suppose a new company policy says that instead of the monthly salary we will now store the yearly salary. We will need to make this change inside Employee and support the new usage, without breaking existing code (such as the old main) that relies on the old version.

Remove the monthly salary instance variable from Employee and add an instance variable for yearly salary (with accessor and mutator).

Change the existing public accessor and mutator for the monthly salary so that they will still work as originally expected, that is, the existing main method, unchanged, will have the same results it did when you ran it for part A, but inside Employee we are using the new instance variable. We should also be able to write new code using Employee that works with yearly salaries directly.

Think this through. If someone tries to setYearlySalary(50000) what would they expect to happen? If someone tries to setMonthlySalary(1000) what would they expect to happen? Does your code do this?

Add a new class with a main, NewEmployeeHarness, and test the additions to Employee.

Part C

Add a new class Position, which has a String title, a double bonus (must be non-negative), and an Employee worker. Include the usual methods, and a parameterized constructor that takes title and bonus.

In the mutator for worker, if the worker passed in is not null, increase that worker's yearly salary by the bonus.

Whenever the bonus for the position is changed, update the salary for the worker by the same amount (if there is a worker). (That is, if the bonus goes from 100 to 150, we'd only add the 50 to the salary, since they already got the 100 when they became the worker). You can assume bonuses only increase. (You don't have to worry about the worker losing the bonus when replaced by another worker)

Test the class Position later in the same main as for part B.

I have done all of part A, Here is what i have done to this point:

Employee Class

public class Employee {

private String firstName;
private String lastName;
private double monthlySalary;

//constructor to set class variables
public Employee(String firstName, String lastName,
double monthlySalary) {
this.firstName = firstName;
this.lastName = lastName;
this.monthlySalary = monthlySalary;
}

public String getFirstName() {
return firstName;
}

public void setFirstName(String firstName) {
this.firstName = firstName;
}

public String getLastName() {
return lastName;
}

public void setLastName(String lastName) {
this.lastName = lastName;
}

public void setMonthlySalary(double monthlySalary) {
this.monthlySalary = monthlySalary;
}

public void raiseSalary() {
monthlySalary = monthlySalary + monthlySalary + 0.10;
}

  
}//end of Employee class

Test

public class EmployeeMain {

public static void main(String[] args) {
// 2 Instances of employees
Employee emp1 = new Employee("John", "Doe", 16000);
Employee emp2 = new Employee("Jane", "Doe", 13000);
  
int Number_of_Months = 12;
  
  
System.out.printf("emp1 yearly salary %5.2f \n",
emp1.getMonthlySalary() * Number_of_Months);
System.out.printf("emp2 yearly salary %5.2f \n",
emp2.getMonthlySalary() * Number_of_Months);

//print salary 10 % on monthly salary
emp1.raiseSalary();
emp2.raiseSalary();

//print new yearly salary
System.out.printf("emp1 new yearly salary %5.2f \n",
emp1.getMonthlySalary() * Number_of_Months);
System.out.printf("emp2 new yearly salary %5.2f \n",
emp2.getMonthlySalary() * Number_of_Months);
}
}

Answer 1

Please find the classes needed for Part A,B and C:

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

package test;

//class Employee
public class Employee {

private String firstName;
private String lastName;
//private double monthlySalary;
private double yearlySalary;

//constructor to set class variables
public Employee(String firstName, String lastName,double monthlySalary) {
   this.firstName = firstName;
   this.lastName = lastName;
   //this.monthlySalary = monthlySalary;
   this.setMonthlySalary(monthlySalary);//change for Part B
}

public String getFirstName() {
   return firstName;
}

public void setFirstName(String firstName) {
   this.firstName = firstName;
}

public String getLastName() {
   return lastName;
}

public void setLastName(String lastName) {
   this.lastName = lastName;
}
public double getMonthlySalary(){
   //return this.monthlySalary;
   return (this.yearlySalary/12);//change for Part B
}
public void setMonthlySalary(double monthlySalary) {
   //this.monthlySalary = monthlySalary;
   this.yearlySalary = monthlySalary * 12;//change for Part B
}

public void raiseSalary() {
   //monthlySalary = monthlySalary + monthlySalary * 0.10;
   this.yearlySalary = this.yearlySalary + this.yearlySalary*0.10;//change for part B
}

//getter and setter for yearlySalary

public double getYearlySalary() {
   return yearlySalary;
}

public void setYearlySalary(double yearlySalary) {
   this.yearlySalary = yearlySalary;
}

  
}//end of Employee class

//////////////////////////////////Position.java//////////////////////////////

package test;

//Class Position
public class Position {
   //private fields
   private String title;
   private double bonus;
   private Employee worker;
  
   //constructor with title and bonus
   public Position(String title, double bonus) {
       this.title = title;
       this.bonus = bonus;
   }

   //getter for title
   public String getTitle() {
       return title;
   }
   //setter for title
   public void setTitle(String title) {
       this.title = title;
   }
   //getter for bonus
   public double getBonus() {
       return bonus;
   }
   //setter for bonus
   public void setBonus(double bonus) {
       double existingBonus = this.bonus; //get the existing bonus
       this.bonus = bonus; //set new bonus
       //assuming bonus will always increase get the increased bonus amount
       double increasedBonusAmount = this.bonus - existingBonus;
       if(this.worker!=null){
           //adjust worker's yerly salary with the i ncreased amount
           this.worker.setYearlySalary(worker.getYearlySalary()+increasedBonusAmount);
       }
   }

   //getter for worker
   public Employee getWorker() {
       return worker;
   }

   //setter for worker
   public void setWorker(Employee worker) {
       if(worker!=null){
           this.worker = worker;//updateworker instance field
           //update worker's yearly salary with bonus
           this.worker.setYearlySalary(worker.getYearlySalary()+bonus);
       }
   }

}

//////////////////////////////////EmployeeMain.java/////////////////////////////////////

package test;

public class EmployeeMain {

public static void main(String[] args) {
   // 2 Instances of employees
   Employee emp1 = new Employee("John", "Doe", 16000);
   Employee emp2 = new Employee("Jane", "Doe", 13000);
  
   int Number_of_Months = 12;
  
  
   System.out.printf("emp1 yearly salary %5.2f \n",
   emp1.getMonthlySalary() * Number_of_Months);
   System.out.printf("emp2 yearly salary %5.2f \n",
   emp2.getMonthlySalary() * Number_of_Months);
  
   //print salary 10 % on monthly salary
   emp1.raiseSalary();
   emp2.raiseSalary();
  
   //print new yearly salary
   System.out.printf("emp1 new yearly salary %5.2f \n",
   emp1.getMonthlySalary() * Number_of_Months);
   System.out.printf("emp2 new yearly salary %5.2f \n",
   emp2.getMonthlySalary() * Number_of_Months);
  
   //PartB test
   Employee NewEmployeeHarness = new Employee("Harness","Williams",15000);
  
   //calling existing method getMonthlySalary
   System.out.printf("\n\n(Through getMonthlySalary Call)NewEmployeeHarness yearly salary %5.2f \n",
           NewEmployeeHarness.getMonthlySalary() * Number_of_Months);
   //calling new getter for yearly salary
   System.out.printf("(Through getYearlySalary Call)NewEmployeeHarness yearly salary %5.2f \n",
           NewEmployeeHarness.getYearlySalary());
  
   NewEmployeeHarness.setMonthlySalary(16000); //set monthly salary by existing method
   System.out.println("\n\nYearly salary is set by existing setMonthlySalary method.");
   System.out.printf("\nMonthly salary: %5.2f ", NewEmployeeHarness.getMonthlySalary());
   System.out.printf("\nYearly salary: %5.2f ", NewEmployeeHarness.getYearlySalary());
  
   NewEmployeeHarness.setYearlySalary(204000); //set yearly salary by new method
   System.out.println("\n\nYearly salary is set by new setYearlySalary method.");
   System.out.printf("\nMonthly salary: %5.2f ", NewEmployeeHarness.getMonthlySalary());
   System.out.printf("\nYearly salary: %5.2f ", NewEmployeeHarness.getYearlySalary());
  
   NewEmployeeHarness.raiseSalary();
   System.out.println("\n\nYearly salary is raised by 10% through raiseSalary method.");
   System.out.printf("\nMonthly salary: %5.2f ", NewEmployeeHarness.getMonthlySalary());
   System.out.printf("\nYearly salary: %5.2f ", NewEmployeeHarness.getYearlySalary());
  
  
   //Part C
   //Create a Developer position with Bonus 500.00
   Position pos1 = new Position("Developer",500.00);
   pos1.setWorker(emp1); //set emp1 in this position
  
   if(pos1.getWorker()!=null){
       System.out.printf("\nYearly salary of %s %s in %s Position (with bonus %5.2f) is %5.2f",
       pos1.getWorker().getFirstName(),pos1.getWorker().getLastName(),pos1.getTitle(),
       pos1.getBonus(),pos1.getWorker().getYearlySalary());
   }
  
   //Create a Tester position with Bonus 400.00
   Position pos2 = new Position("Tester",400.00);
   pos2.setWorker(NewEmployeeHarness);//set NewEmployeeHarness for this position
  
   if(pos2.getWorker()!=null){
       System.out.printf("\nYearly salary of %s %s in %s Position (with bonus %5.2f) is %5.2f",
       pos2.getWorker().getFirstName(),pos2.getWorker().getLastName(),pos2.getTitle(),
       pos2.getBonus(),pos2.getWorker().getYearlySalary());
      
       //update bonus for tester position
       pos2.setBonus(475.00); //bonus for position 2 has changed from 400 to 475
      
       System.out.printf("\nYearly salary of %s %s in %s Position (with bonus %5.2f) is %5.2f",
       pos2.getWorker().getFirstName(),pos2.getWorker().getLastName(),pos2.getTitle(),
       pos2.getBonus(),pos2.getWorker().getYearlySalary());
   }
  

}
}

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

OUTPUT

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

emp1 yearly salary 192000.00
emp2 yearly salary 156000.00
emp1 new yearly salary 211200.00
emp2 new yearly salary 171600.00

(Through getMonthlySalary Call)NewEmployeeHarness yearly salary 180000.00
(Through getYearlySalary Call)NewEmployeeHarness yearly salary 180000.00

Yearly salary is set by existing setMonthlySalary method.

Monthly salary: 16000.00
Yearly salary: 192000.00

Yearly salary is set by new setYearlySalary method.

Monthly salary: 17000.00
Yearly salary: 204000.00

Yearly salary is raised by 10% through raiseSalary method.

Monthly salary: 18700.00
Yearly salary: 224400.00
Yearly salary of John Doe in Developer Position (with bonus 500.00) is 211700.00
Yearly salary of Harness Williams in Tester Position (with bonus 400.00) is 224800.00
Yearly salary of Harness Williams in Tester Position (with bonus 475.00) is 224875.00