Question

Registration

Language Java

Step 1:
Design a class called Student.

The Student class should contain the following data:
firstName
lastName
studentID
totalCredits
gpa

Your class should implement the “sets” and “gets” for the class. Include methods: equals, compareTo, toString. Change the toString method (from class) to put each member variable on a new line.

Step 2:
Write a driver program to test that Student works correctly. Test is with 3 students as given in class.

Step 3:
Write a “registration” program that will store up to students (for now) in an array roster of Student objects.
After the user has entered the information for the 5 students, use the InsertionSort code written in class, and posted on Blackboard, to sort the array roster.

Step 4:
Write a method called storeRosterthat will save the data in the array roster to a text file Roster1.txt.

Step 5:
Write a method called loadRoster that will read the data in Roster1.txt into an array roster. (Note: this data will already be sorted!)

Answer 1

thanks for the question, Please post only one question at a time, the whole assignment was too big to be completed in the given time. Please break your questions into sub questions and post. Also, you have not shared the insertSort() code written in in your class. I had to do that also.

Nevertheless, I have implemented the complete assignment and commented the section each part/Step as asked in the question.

Here is the full code.

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

public class Student implements Comparable<Student> {

    private String firstName;
    private String lastName;
    private String studentId;
    private int totalCredits;
    private double gpa;

   public Student() {
        this.firstName = "";
        this.lastName = "";
        this.studentId = "";
        this.totalCredits = 0;
        this.gpa = 0;
    }

    public Student(String firstName, String lastName, String studentId, int totalCredits, double gpa) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.studentId = studentId;
        this.totalCredits = totalCredits;
        this.gpa = gpa;
    }

    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 String getStudentId() {
        return studentId;
    }

    public void setStudentId(String studentId) {
        this.studentId = studentId;
    }

    public int getTotalCredits() {
        return totalCredits;
    }

    public void setTotalCredits(int totalCredits) {
        this.totalCredits = totalCredits;
    }

    public double getGpa() {
        return gpa;
    }

    public void setGpa(double gpa) {
        this.gpa = gpa;
    }

    @Override
    public boolean equals(Object o) {
       if (o == null || !(o instanceof Student)) return false;
        Student aStudent = (Student) o;
        return aStudent.getFirstName().equals(getFirstName()) &&
                aStudent.getLastName().equals(getLastName()) &&
                aStudent.getStudentId().equals(getStudentId());
    }


    @Override
    public String toString() {
        return
                "First name: " + firstName +
                        "\nLast Name: " + lastName +
                        "\nStudent Id: " + studentId +
                        "\nTotal credits: " + totalCredits +
                        "\ngpa:" + gpa;

    }

    @Override
    public int compareTo(Student student) {
        if (getFirstName().compareTo(student.getFirstName()) == 0) {
            if (getLastName().compareTo(student.getLastName()) == 0) {
                return getStudentId().compareTo(student.getStudentId());

            } else {
                return getLastName().compareTo(student.getLastName());
            }
        } else {
            return getFirstName().compareTo(student.getFirstName());
        }
    }
}

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

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileWriter;

import java.io.IOException;

import java.util.Arrays;

import java.util.Scanner;



public class Registration {



    public static void main(String[] args) {



        // Below code is for Step 2

        Student students[] = new Student[3];

        students[0] = new Student("John", "Doe", "123-45", 40, 4.6);

        students[1] = new Student("John", "Smith", "124-45", 50, 4.7);

        students[2] = new Student("Alan", "Donald", "127-65", 30, 2.7);



        // printing the students

        for (Student student : students) {

            System.out.println(student);

        }



        Arrays.sort(students);

        //insertionSort(students);

        System.out.println("====================");

        System.out.println("Sorting the students");

        System.out.println("====================");



        // printing the students again

        for (Student student : students) {

            System.out.println(student);

        }



        // Step 3



        Student fiveStudents[] = {new Student(), new Student(), new Student(), new Student(), new Student()};

        Scanner scanner = new Scanner(System.in);

        for (int i = 0; i < fiveStudents.length; i++) {

            System.out.println("Student " + (i + 1));

            System.out.print("Enter First Name: ");

            fiveStudents[i].setFirstName(scanner.nextLine());

            System.out.print("Enter Last Name: ");

            fiveStudents[i].setLastName(scanner.nextLine());

            System.out.print("Enter Student ID: ");

            fiveStudents[i].setStudentId(scanner.nextLine());

            System.out.print("Enter total credits (whole number) : ");

            fiveStudents[i].setTotalCredits(scanner.nextInt());

            System.out.print("Enter GPA score: ");

            fiveStudents[i].setGpa(scanner.nextDouble());

            scanner.nextLine();

        }



        insertionSort(fiveStudents);



        // printing the students entered by the user

        for (Student student : fiveStudents) {

            System.out.println(student);

        }



        storeRoster(fiveStudents);

        loadRoster();



    }



    // Step 5

    public static Student[] loadRoster() {



        Student students[] = new Student[5];

        int index = 0;

        String fileName = "Roster1.txt";

        try {

            Scanner fileReader = new Scanner(new File(fileName));

            while (fileReader.hasNextLine()) {

                String tokens[] = fileReader.nextLine().split("\\s+");

                if (tokens.length == 5) {



                    int credits = Integer.parseInt(tokens[3]);

                    double gpa = Double.parseDouble(tokens[4]);



                    students[index++] = new Student(tokens[0], tokens[1], tokens[2], credits, gpa);

                }

            }

        } catch (FileNotFoundException e) {

            System.out.println("Error: Unable to read/open file: " + fileName);

        }



        // printing the students after reading from the file

        System.out.println("=================================================");

        System.out.println("printing the students after reading from the file");

        System.out.println("=================================================");

        for (Student student : students) {

            System.out.println(student);

        }

        return students;

    }



    // Part Step 4

    public static void storeRoster(Student[] students) {

        String fileName = "Roster1.txt";

        try {

            FileWriter writer = new FileWriter(new File(fileName));

            for (Student student : students) {

                writer.write(student.getFirstName() + " ");

                writer.write(student.getLastName() + " ");

                writer.write(student.getStudentId() + " ");

                writer.write(student.getTotalCredits() + " ");

                writer.write(student.getGpa() + "\r\n");

                writer.flush();

            }

            writer.close();

            System.out.println(fileName + " updated successfully");

        } catch (IOException e) {

            System.out.println("Error: Unable to write/open file: " + fileName);

        }

    }



    public static void insertionSort(Student[] students) {



        int n = students.length;

        for (int i = 1; i < n; i++) {

            Student key = students[i];

            int j = i - 1;

            while (j >= 0 && students[j].compareTo(key) > 0) {

                students[j + 1] = students[j];

                j = j - 1;

            }

            students[j + 1] = key;

        }

    }

}

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