Question

Java Programming COMP-228

LAB ASSIGNMENT #1

>> Apply the naming conventions for variables, methods, classes, and packages:

- variable names start with a lowercase character for the first word and uppercase for every other word

- classes start with an uppercase character of every word

- packages use only lowercase characters

- methods start with a lowercase character for the first word and uppercase for every other word Java Programming COMP-228

Exercise #1: [5 marks]

Write a Java application using eclipse as IDE, that implements the following class(es) as per business requirements mentioned below:

Create a CommissionEmployee class (CommissionEmployee.java) that has the following instance variables:

- Employee ID, first name, last name, gross sales ( amount in dollars) and commission rate. Define their data types appropriately.

- Define only getters for employee ID, first name, last name. Ensure the proper ( no negative and null values ) data values entered by implementing data validations.

- Define getter and setter for gross sales and commission rate. Ensure the values for them should never be negative or zero.

- Commission rate should be between 0.1 and 1.0%. Set default value 0.1.

- Class should have defined two overloaded constructors:

o One for initializing all the instance data members/variables

o Second for initializing employee ID, first name, last name

- Define a public method - double earnings() which calculates employee’s commission ( commission rate * gross sales/100)

- Define a public method – String toString() which is used to display the object’s data

Create another BasePlusCommissionEmployee class (BasePlusCommissionEmployee.java) that has the following instance variables:

- Employee ID, First name, last name, base salary, gross sales ( amount in dollars) and commission rate. Define their data types appropriately.

- Define only getters for employee ID, first name, last name and base salary. Ensure the proper ( no negative and null values ) data values by implementing data validations.

- Use default value of 200.00 dollars for base salary for all the employees.

- Define getter and setter for gross sales and commission rate. Ensure the values for them should never be negative or zero.

- Commission rate should be between 0.1 and 1.0%. Set default value 0.1.

- Class should have defined two overloaded constructors:

o One for initializing all the instance data members

o Second for initializing employee ID, first name, last name, base salary only ( if you want to set it more than 200.00 dollars)

- Define a public method - double earnings() which calculates employee’s commission ( commission rate * gross sales/100 + base salary )

- Define a public method – String toString() which is used to display the object’s data

Create a HourlyEmployee class (HourlyEmployee.java) that has the following instance variables:

- Employee ID, first name, last name, total number of hours worked per week, and hourly rate ( amount in dollars). Define their data types appropriately.

- Define only getters for employee ID, first name, last name. Ensure the proper (no negative and null values ) data values by implementing data validations.

Java Programming COMP-228

- Define getters and setters for number of hours worked per week and hourly rate. Ensure the values for them should never be negative or zero.

- Hourly rate should be minimum 14.00 dollars per hour.

- Class should have defined two overloaded constructors:

o One for initializing all the instance data members/variables

o Second for initializing employee ID, first name, last name

- Define a public method - double earnings() which calculates employee’s commission (number of hours worked per week * commission rate)

- Define a public method – String toString() which is used to display the object’s data

Create a driver class EmployeeTest (EmployeeTest.java) which tests above classes by at least creating one object each of CommissionEmployee, BasePlusCommissionEmployee and HourlyEmployee classes.

Answer 1

Please find the answer below, have defined all the details in the comments. Code is developed as per the instructions are given in the question.

CommissionEmployee.java

//CommissionEmployee.java class
public class CommissionEmployee {
    //private date members of the class
    private int employeeId;
    private String firstName;
    private String lastName;
    private double grossSales;
    //default value for the commission rate to 0.1
    private double commissionRate = 0.1;

    //getter methods
    public int getEmployeeId() {
        return employeeId;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    //getter and setter for the grossSales and commissionRate
    public double getGrossSales() {
        return grossSales;
    }

    public void setGrossSales(double grossSales) {
        if(grossSales > 0) {
            this.grossSales = grossSales;
        }
    }

    public double getCommissionRate() {
        return commissionRate;
    }

    public void setCommissionRate(double commissionRate) {
        if(commissionRate > 0 && (commissionRate >= 0.1 && commissionRate<=1.0)) {
            this.commissionRate = commissionRate;
        }
    }

    //constructor 1
    public CommissionEmployee(int employeeId, String firstName, String lastName, double grossSales, double commissionRate) {
        if(employeeId > 0)
            this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
        if(grossSales > 0)
            this.grossSales = grossSales;
        if(commissionRate > 0 && (commissionRate >= 0.1 && commissionRate<=1.0))
            this.commissionRate = commissionRate;
    }

    //constructor 2
    public CommissionEmployee(int employeeId, String firstName, String lastName) {
        if(employeeId > 0)
            this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    //earnings to calculate the earning of the employee
    public double earnings(){
        double commission = 0;
        commission = (this.commissionRate*this.grossSales)/100.0;
        return commission;
    }

    //to string method to print the details
    @Override
    public String toString() {
        return "CommissionEmployee{" +
                "employeeId=" + employeeId +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", grossSales=" + grossSales +
                ", commissionRate=" + commissionRate +
                '}';
    }
}

BasePlusCommissionEmployee.java

public class BasePlusCommissionEmployee {
    //private date members of the class
    private int employeeId;
    private String firstName;
    private String lastName;
    //default value for the base salary
    private double baseSalary = 200.00;
    private double grossSales;
    //default value for the commission rate to 0.1
    private double commissionRate = 0.1;

    //getters
    public int getEmployeeId() {
        return employeeId;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public double getBaseSalary() {
        return baseSalary;
    }

    //getter and setter for the grossSales and commissionRate
    public double getGrossSales() {
        return grossSales;
    }

    public void setGrossSales(double grossSales) {
        if(grossSales > 0) {
            this.grossSales = grossSales;
        }
    }

    public double getCommissionRate() {
        return commissionRate;
    }

    public void setCommissionRate(double commissionRate) {
        if(commissionRate > 0 && (commissionRate >= 0.1 && commissionRate<=1.0)) {
            this.commissionRate = commissionRate;
        }
    }

    //constructor 1
    public BasePlusCommissionEmployee(int employeeId, String firstName, String lastName, double baseSalary, double grossSales, double commissionRate) {
        if(employeeId > 0)
            this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
        if(baseSalary > 0)
            this.baseSalary = baseSalary;
        if(grossSales > 0)
            this.grossSales = grossSales;
        if(commissionRate > 0 && (commissionRate >= 0.1 && commissionRate<=1.0))
            this.commissionRate = commissionRate;
    }

    //constructor 2
    public BasePlusCommissionEmployee(int employeeId, String firstName, String lastName, double baseSalary) {
        if(employeeId > 0)
            this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
        if(baseSalary > 200)
            this.baseSalary = baseSalary;
    }

    //earnings to calculate employee's earnings
    public double earnings(){
        double commision = ((this.commissionRate * this.grossSales)/100.0) + this.baseSalary;
        return commision;
    }

    //tostring the print the object details
    @Override
    public String toString() {
        return "BasePlusCommissionEmployee{" +
                "employeeId=" + employeeId +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", baseSalary=" + baseSalary +
                ", grossSales=" + grossSales +
                ", commissionRate=" + commissionRate +
                '}';
    }
}

HourlyEmployee.java

public class HourlyEmployee {
    //private date members of the class
    private int employeeId;
    private String firstName;
    private String lastName;
    private double totalHoursWroked;
    //default value for the hourly rate
    private double hourlyRate = 14.00;


    //getters
    public int getEmployeeId() {
        return employeeId;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    //getters and setters

    public double getTotalHoursWroked() {
        return totalHoursWroked;
    }

    public void setTotalHoursWroked(double totalHoursWroked) {
        if(totalHoursWroked > 0)
            this.totalHoursWroked = totalHoursWroked;
    }

    public double getHourlyRate() {
        return hourlyRate;
    }

    public void setHourlyRate(double hourlyRate) {
        if(hourlyRate > 0)
            this.hourlyRate = hourlyRate;
    }

    //constructor 1
    public HourlyEmployee(int employeeId, String firstName, String lastName, double totalHoursWroked, double hourlyRate) {
        if(employeeId > 0)
            this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
        if(totalHoursWroked > 0)
            this.totalHoursWroked = totalHoursWroked;
        if(hourlyRate > 0)
            this.hourlyRate = hourlyRate;
    }

    //constructor 2
    public HourlyEmployee(int employeeId, String firstName, String lastName) {
        if(employeeId > 0)
            this.employeeId = employeeId;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    //calculate the employee's earnings
    public double earnings(){
        double commision  = (this.totalHoursWroked * this.hourlyRate);
        return commision;
    }

    //print the object details
    @Override
    public String toString() {
        return "HourlyEmployee{" +
                "employeeId=" + employeeId +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", totalHoursWroked=" + totalHoursWroked +
                ", hourlyRate=" + hourlyRate +
                '}';
    }
}

EmployeeTest.java

public class EmployeeTest {
    public static void main(String[] args) {
        CommissionEmployee cme = new CommissionEmployee(1,"John","Jacob",100000,0.5);
        System.out.println("Commission Employee Details: ");
        System.out.println(cme);
        System.out.println("Commission Employee Earnings: " + cme.earnings());
        System.out.println();

        BasePlusCommissionEmployee bcme = new BasePlusCommissionEmployee(2,"Any","Kay",500,100000,0.5);
        System.out.println("Base plus Commission Employee Details: ");
        System.out.println(bcme);
        System.out.println("Base plus Commission Employee Earnings: " + bcme.earnings());
        System.out.println();

        HourlyEmployee he = new HourlyEmployee(3,"Neil","Smith",50,20);
        System.out.println("Hourly Employee Details: ");
        System.out.println(he);
        System.out.println("Hourly Employee Earnings: " + he.earnings());
    }
}

Output: