Description
In chapter 9 of your Deitel & Deitel text, you studied an inheritance hierarchy in which class BasePlusCommissionEmployee inherited from class CommissionEmployee. However, not all types of employees are CommissionEmployees.
In this exercise, you’ll create a more general Employee superclass that factors out the attributes and behaviors in class CommissionEmployee that are common to all Employees. The common attributes and behaviors for all Employees are firstName, lastName, socialSecurityNumber, getFirstName, getLastName, getSocialSecurityNumber and a portion of method toString.
Create a new superclass Employee that contains these instance variables and methods and a constructor.
Next, rewrite class CommissionEmployee from Section 9.4.5 as a subclass of Employee. Class CommissionEmployee should contain only the instance variables and methods that are not declared in superclass Employee. Class CommissionEmployee’s constructor should invoke class Employee’s constructor and CommissionEmployee’s toString method should invoke Employee’s toString method.
Once you’ve completed these modifications, run the BasePlusCommissionEmployeeTest app using these new classes to ensure that the app still displays the same results for a BasePlusCommissionEmployee object.
Make sure that your screen shots show your program running and that your runtime display shows that your program does all that is required of it. You only get credit for what you demonstrate.
Submit this assignment by 11:59 p.m. (ET) on Monday of Module/Week 2.
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// Fig. 9.10: CommissionEmployee.java// CommissionEmployee class uses methods to manipulate its // private instance variables.public class CommissionEmployee{   private final String firstName;                                private final String lastName;                                 private final String socialSecurityNumber;                     private double grossSales; // gross weekly sales         private double commissionRate; // commission percentage   // five-argument constructor   public CommissionEmployee(String firstName, String lastName,       String socialSecurityNumber, double grossSales,       double commissionRate)   {      // implicit call to Object constructor occurs here      // if grossSales is invalid throw exception      if (grossSales < 0.0)          throw new IllegalArgumentException(            "Gross sales must be >= 0.0");      // if commissionRate is invalid throw exception      if (commissionRate <= 0.0 || commissionRate >= 1.0)         throw new IllegalArgumentException(            "Commission rate must be > 0.0 and < 1.0");      this.firstName = firstName;                                         this.lastName = lastName;                                         this.socialSecurityNumber = socialSecurityNumber;              this.grossSales = grossSales;      this.commissionRate = commissionRate;   } // end constructor    // return first name   public String getFirstName()   {      return firstName;   }   // return last name   public String getLastName()   {      return lastName;   }   // return social security number   public String getSocialSecurityNumber()   {      return socialSecurityNumber;   }    // set gross sales amount   public void setGrossSales(double grossSales)   {      if (grossSales < 0.0)          throw new IllegalArgumentException(            "Gross sales must be >= 0.0");      this.grossSales = grossSales;   }    // return gross sales amount   public double getGrossSales()   {      return grossSales;   }    // set commission rate   public void setCommissionRate(double commissionRate)   {      if (commissionRate <= 0.0 || commissionRate >= 1.0)         throw new IllegalArgumentException(            "Commission rate must be > 0.0 and < 1.0");      this.commissionRate = commissionRate;   }    // return commission rate   public double getCommissionRate()   {      return commissionRate;   }   // calculate earnings   public double earnings()   {      return getCommissionRate() * getGrossSales();   }    // return String representation of CommissionEmployee object   @Override    public String toString()   {      return String.format("%s: %s %s%n%s: %s%n%s: %.2f%n%s: %.2f",          "commission employee", getFirstName(), getLastName(),          "social security number", getSocialSecurityNumber(),          "gross sales", getGrossSales(),          "commission rate", getCommissionRate());   } } // end class CommissionEmployee// Fig. 9.11: BasePlusCommissionEmployee.java// BasePlusCommissionEmployee class inherits from CommissionEmployee // and accesses the superclass’s private data via inherited // public methods.public class BasePlusCommissionEmployee extends CommissionEmployee{   private double baseSalary; // base salary per week   // six-argument constructor   public BasePlusCommissionEmployee(String firstName, String lastName,       String socialSecurityNumber, double grossSales,       double commissionRate, double baseSalary)   {      super(firstName, lastName, socialSecurityNumber,          grossSales, commissionRate);                           // if baseSalary is invalid throw exception      if (baseSalary < 0.0)                           throw new IllegalArgumentException(            "Base salary must be >= 0.0");       this.baseSalary = baseSalary;   }      // set base salary   public void setBaseSalary(double baseSalary)   {      if (baseSalary < 0.0)                           throw new IllegalArgumentException(            "Base salary must be >= 0.0");       this.baseSalary = baseSalary;                  }    // return base salary   public double getBaseSalary()   {      return baseSalary;   }    // calculate earnings   @Override    public double earnings()   {      return getBaseSalary() + super.earnings();   }   // return String representation of BasePlusCommissionEmployee   @Override   public String toString()   {      return String.format("%s %s%n%s: %.2f", "base-salaried",         super.toString(), "base salary", getBaseSalary());     } } // end class BasePlusCommissionEmployee// BasePlusCommissionEmployeeTest.java// Testing class BasePlusCommissionEmployee.public class BasePlusCommissionEmployeeTest{   public static void main(String[] args)    {      // instantiate CommissionEmployee object      CommissionEmployee employee1 = new CommissionEmployee(         "Sue", "Jones", "222-22-2222", 10000, .06);                 // get commission employee data      System.out.println(         "Employee information obtained by get methods:");      System.out.printf("%n%s %s%n", "First name is",         employee1.getFirstName());      System.out.printf("%s %s%n", "Last name is",          employee1.getLastName());      System.out.printf("%s %s%n", "Social security number is",          employee1.getSocialSecurityNumber());      System.out.printf("%s %.2f%n", "Gross sales is",          employee1.getGrossSales());      System.out.printf("%s %.2f%n", "Commission rate is",         employee1.getCommissionRate());      employee1.setGrossSales(5000);       employee1.setCommissionRate(.1);             System.out.printf("%n%s:%n%n%s%n",                                        "Updated employee information obtained by toString", employee1);            // instantiate BasePlusCommissionEmployee object      BasePlusCommissionEmployee employee2 =          new BasePlusCommissionEmployee(            "Bob", "Lewis", "333-33-3333", 5000, .04, 300);            // get base-salaried commission employee data      System.out.println(         "Employee information obtained by get methods:");      System.out.printf("%n%s %s%n", "First name is",         employee2.getFirstName());      System.out.printf("%s %s%n", "Last name is",          employee2.getLastName());      System.out.printf("%s %s%n", "Social security number is",          employee2.getSocialSecurityNumber());      System.out.printf("%s %.2f%n", "Gross sales is",          employee2.getGrossSales());      System.out.printf("%s %.2f%n", "Commission rate is",         employee2.getCommissionRate());      System.out.printf("%s %.2f%n", "Base salary is",         employee2.getBaseSalary());      employee2.setBaseSalary(1000);             System.out.printf("%n%s:%n%n%s%n",          "Updated employee information obtained by toString",          employee2.toString());   } // end main} // end class BasePlusCommissionEmployeeTest |
