Main.java

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        StudentService service = new StudentService();

        while (true) {

            System.out.println("\n==========================================");
            System.out.println("      STUDENT MANAGEMENT SYSTEM");
            System.out.println("==========================================");
            System.out.println("1. Add Student");
            System.out.println("2. View Students");
            System.out.println("3. Search Student");
            System.out.println("4. Update Student");
            System.out.println("5. Delete Student");
            System.out.println("6. Exit");
            System.out.print("Enter your choice: ");

            int choice = sc.nextInt();
            sc.nextLine();

            switch (choice) {

                case 1:

                    System.out.println("\n------ Add Student ------");

                    System.out.print("Enter ID: ");
                    int id = sc.nextInt();
                    sc.nextLine();

                    System.out.print("Enter Name: ");
                    String name = sc.nextLine();

                    System.out.print("Enter Branch: ");
                    String branch = sc.nextLine();

                    int year;

                    while (true) {
                        System.out.print("Enter Year (1-4): ");
                        year = sc.nextInt();

                        if (year >= 1 && year <= 4) {
                            break;
                        }

                        System.out.println("Invalid Year! Please enter between 1 and 4.");
                    }

                    sc.nextLine();

                    System.out.print("Enter Phone: ");
                    String phone = sc.nextLine();

                    Student student = new Student(id, name, branch, year, phone);

                    service.addStudent(student);

                    break;

                case 2:

                    service.viewStudents();

                    break;

                case 3:

                    System.out.print("Enter Student ID to Search: ");
                    int searchId = sc.nextInt();

                    service.searchStudent(searchId);

                    break;

                case 4:

                    System.out.print("Enter Student ID to Update: ");
                    int updateId = sc.nextInt();
                    sc.nextLine();

                    System.out.print("Enter New Name: ");
                    String newName = sc.nextLine();

                    System.out.print("Enter New Branch: ");
                    String newBranch = sc.nextLine();

                    int newYear;

                    while (true) {

                        System.out.print("Enter New Year (1-4): ");
                        newYear = sc.nextInt();

                        if (newYear >= 1 && newYear <= 4) {
                            break;
                        }

                        System.out.println("Invalid Year!");
                    }

                    sc.nextLine();

                    System.out.print("Enter New Phone: ");
                    String newPhone = sc.nextLine();

                    service.updateStudent(updateId, newName, newBranch, newYear, newPhone);

                    break;

                case 5:

                    System.out.print("Enter Student ID to Delete: ");
                    int deleteId = sc.nextInt();
                    sc.nextLine();

                    System.out.print("Are you sure? (yes/no): ");
                    String confirm = sc.nextLine();

                    if (confirm.equalsIgnoreCase("yes")) {
                        service.deleteStudent(deleteId);
                    } else {
                        System.out.println("Delete Cancelled.");
                    }

                    break;

                case 6:

                    System.out.println("\n==========================================");
                    System.out.println(" Thank You for using");
                    System.out.println(" STUDENT MANAGEMENT SYSTEM");
                    System.out.println("------------------------------------------");
                    System.out.println(" Developed by: Thota Usha Laharika");
                    System.out.println("==========================================");

                    sc.close();
                    System.exit(0);

                default:

                    System.out.println("Invalid Choice! Please try again.");
            }

        }

    }

}