Answer Happy

import java.util.Objects;
public class Course {
private String courseNum, courseName;
private int credits, section;

public Course()
{
this.courseNum = "";
this.courseName = "";;
this.credits = 0;
this.section = 0;
}
public Course(String courseNum, String courseName, int credits,
int section) {
this.courseNum = courseNum;
this.courseName = courseName;
this.credits = credits;
this.section = section;
}
public String getCourseNum() {
return courseNum;
}
public void setCourseNum(String courseNum) {
this.courseNum = courseNum;
}
public String getCourseName() {
return courseName;
}
public void setCourseName(String courseName) {
this.courseName = courseName;
}
public int getCredits() {
return credits;
}
public void setCredits(int credits) {
this.credits = credits;
}
public int getSection() {
return section;
}
public void setSection(int section) {
this.section = section;
}
@Override
public int hashCode() {
int hash = 5;
return hash;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Course other = (Course) obj;
if (this.credits != other.credits) {
return false;
}
if (this.section != other.section) {
return false;
}
if (!Objects.equals(this.courseNum, other.courseNum)) {
return false;
}
if (!Objects.equals(this.courseName, other.courseName)) {
return false;
}
return true;
}

@Override
public String toString()
{
return ("Course Number: " + getCourseNum() + ", Course Name: " +
getCourseName()
+ ", Credits: " + getCredits() + ", Section: " +
getSection());
}
}
Student.java
import java.util.ArrayList;
public class Student {
private long idNum;
private String firstName, lastName;
private char gender;
private String email;
private ArrayList<Course> coursesRegistered;

public Student()
{
this.idNum = 0;
this.firstName = "";
this.lastName = "";
this.gender = 0;
this.email = "";
this.coursesRegistered = null;
}
public Student(long idNum, String firstName, String lastName,
char gender, String email) {
this.idNum = idNum;
this.firstName = firstName;
this.lastName = lastName;
this.gender = gender;
this.email = email;
this.coursesRegistered = new ArrayList<>();
}
public long getIdNum() {
return idNum;
}
public void setIdNum(long idNum) {
this.idNum = idNum;
}
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 char getGender() {
return gender;
}
public void setGender(char gender) {
this.gender = gender;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public ArrayList<Course> getCoursesRegistered() {
return coursesRegistered;
}

public void printCoursesRegistered()
{
if(this.coursesRegistered.isEmpty())
System.out.println("No courses are rgistered till now!");
else
{
System.out.println("Registered Courses:");
for(Course course : this.coursesRegistered)
{
System.out.println(course.toString());
}
System.out.println();
}
}
@Override
public int hashCode() {
int hash = 5;
return hash;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Student other = (Student) obj;
if (this.idNum != other.idNum) {
return false;
}
return true;
}

@Override
public String toString()
{
String res = "Student ID: " + getIdNum() + ", Name: " +
getFirstName() + " " + getLastName()
+ ", Gender: " + getGender() + ", Email: " + getEmail() +
"\n";

if(this.coursesRegistered.isEmpty())
res += "No courses are rgistered till now!";
else
{
res += "Registered Courses:\n";
for(Course course : this.coursesRegistered)
{
res += course.toString() + "\n";
}
res += "\n";
}
return res;
}
}
Roster.java
import java.util.LinkedList;
public class Roster {

private LinkedList<Student> studentsList;
private int size;

public Roster()
{
this.studentsList = new LinkedList<>();
this.size = 0;
}

public boolean addStudent(Student student)
{
boolean found = false;
boolean isAdded;
if(isEmpty())
{
this.studentsList.addLast(student);
this.size++;
isAdded = true;
}
else
{
for(Student s : studentsList)
{
if(s.getIdNum() == student.getIdNum())
{
found = true;
break;
}
}
if(found)
isAdded = false;
else
{
this.studentsList.addLast(student);
this.size++;
isAdded = true;
}
}
return isAdded;
}

public boolean deleteStudent(long id)
{
boolean found = false;
int index = 0;
boolean isDeleted;
for(int i = 0; i < this.studentsList.size(); i++)
{
if(this.studentsList.get(i).getIdNum() == id)
{
found = true;
index = i;
break;
}
}
if(!found)
isDeleted = false;
else
{
this.studentsList.remove(index);
this.size--;
isDeleted = true;
}
return isDeleted;
}

public int searchStudent(long id)
{
boolean found = false;
int index = 0;
for(int i = 0; i < this.studentsList.size(); i++)
{
if(this.studentsList.get(i).getIdNum() == id)
{
found = true;
index = i;
break;
}
}
if(!found)
return -1;
else
return index;
}

public boolean isEmpty(){ return
this.studentsList.isEmpty();}

public int listSize(){ return this.size; }

public void addCourse(Course course, long id)
{
boolean isCoursePresent = false;
boolean isStudentPresent = false;
int studIndex = 0, courseIndex = 0;

for(int i = 0; i < this.studentsList.size(); i++)
{
if(this.studentsList.get(i).getIdNum() == id)
{
isStudentPresent = true;
studIndex = i;
break;
}
}
if(!isStudentPresent)
System.out.println("Student with id " + id + " is not
present.");
else
{
Student stud = this.studentsList.get(studIndex);
for(int i = 0; i < stud.getCoursesRegistered().size();
i++)
{
if(stud.getCoursesRegistered().get(i).getCourseNum().equals(course.getCourseNum()))

{
isCoursePresent = true;
courseIndex = i;
break;
}
}
}

if(isStudentPresent && !isCoursePresent &&
course.getCredits() <= 18)
{
this.studentsList.get(studIndex).getCoursesRegistered().add(course);

System.out.println("Course with course number " +
course.getCourseNum() + " is added successfully.");
}
else
System.out.println("Failed to add the course.");
}

public void deleteCourse(Course course, long studId)
{
boolean isCoursePresent = false;
boolean isStudentPresent = false;
int studIndex = 0, courseIndex = 0;

for(int i = 0; i < this.studentsList.size(); i++)
{
if(this.studentsList.get(i).getIdNum() == studId)
{
isStudentPresent = true;
studIndex = i;
break;
}
}
if(!isStudentPresent)
System.out.println("Student with id " + studId + " is not
present.");
else
{
Student stud = this.studentsList.get(studIndex);
for(int i = 0; i < stud.getCoursesRegistered().size();
i++)
{
if(stud.getCoursesRegistered().get(i).getCourseNum().equals(course.getCourseNum()))

{
isCoursePresent = true;
courseIndex = i;
break;
}
}
}

if(isStudentPresent && isCoursePresent)
{
this.studentsList.get(studIndex).getCoursesRegistered().remove(courseIndex);

System.out.println("Course deleted successfully.");
}
else
System.out.println("Failed to delete the course.");
}

public void printStudentDetails()
{
if(isEmpty())
System.out.println("No student registered!");
else
{
System.out.println("\nAll Students:");
for(Student student : this.studentsList)
{
System.out.println(student.toString() + "\n");
}
System.out.println();
}
}
}
Registration.java (Main class)
import java.util.Scanner;
public class Registration {

public static void main(String[]args)
{
Scanner sc = new Scanner(System.in);
Roster roster = new Roster();
int choice = 0;
do
{
printMenu();
choice = Integer.parseInt(sc.nextLine().trim());
switch(choice)
{
case 1:
{
System.out.print("Enter student id: ");
long id = Long.parseLong(sc.nextLine().trim());
System.out.print("Enter first name: ");
String firstName = sc.nextLine().trim();
System.out.print("Enter last name: ");
String lastName = sc.nextLine().trim();
System.out.print("Enter gender(M/F): ");
char gender = sc.nextLine().trim().toUpperCase().charAt(0);
System.out.print("Enter email: ");
String email = sc.nextLine().trim();
if(roster.addStudent(new Student(id, firstName, lastName, gender,
email)))
System.out.println("Student with id " + id + " is added
successfully.\n");
else
System.out.println("\nFailed to add the student.\n");
break;
}

case 2:
{
System.out.print("Enter the student id: ");
long id = Long.parseLong(sc.nextLine().trim());
if(roster.deleteStudent(id))
System.out.println("Student deleted successfully.");
else
System.out.println("Failed to delete student.");
break;
}

case 3:
{
System.out.print("Enter the course number: ");
String courseNum = sc.nextLine().trim();
System.out.print("Enter the course name: ");
String courseName = sc.nextLine().trim();
System.out.print("Enter credits: ");
int credits = Integer.parseInt(sc.nextLine().trim());
System.out.print("Enter section: ");
int section = Integer.parseInt(sc.nextLine().trim());

Course course = new Course(courseNum, courseName, credits,
section);

System.out.print("Enter the id of the student: ");
long id = Long.parseLong(sc.nextLine().trim());
roster.addCourse(course, id);
break;
}

case 4:
{
System.out.print("Enter the course number: ");
String courseNum = sc.nextLine().trim();
System.out.print("Enter the course name: ");
String courseName = sc.nextLine().trim();
System.out.print("Enter credits: ");
int credits = Integer.parseInt(sc.nextLine().trim());
System.out.print("Enter section: ");
int section = Integer.parseInt(sc.nextLine().trim());

Course course = new Course(courseNum, courseName, credits,
section);

System.out.print("Enter the id of the student: ");
long id = Long.parseLong(sc.nextLine().trim());
roster.deleteCourse(course, id);
break;
}

case 5:
{
roster.printStudentDetails();
break;
}

case 6:
{
System.out.println("\nThank you!\nGood Bye.\n");
System.exit(0);
}

default:
System.out.println("\nInvalid choice.\n");
}
System.out.println();
}while(choice != 6);
}

private static void printMenu()
{
System.out.print("1. Add Student\n2. Delete Student\n3. Add
Course\n4. Delete Course\n5. List all Students"
+ "\n6. Exit\nEnter choice: ");
}
}
Prepare a PowerPoint presentation describing the work done
and how it is done.