end me

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.*;


public class exec{
    @SuppressWarnings("unchecked")
    public static void main(String[] args) throws IOException {
        ArrayList<Course> courses = new ArrayList<Course>();
        ArrayList<Student> students = new ArrayList<Student>();

          try {
                FileInputStream fis = new FileInputStream("courses.ser");
                ObjectInputStream ois = new ObjectInputStream(fis);

                courses =  (ArrayList<Course>) ois.readObject();

                ois.close();
                fis.close(); //serialize
            }
            catch (IOException ioe)
            {
                ioe.printStackTrace();
                return;
            }
            catch (ClassNotFoundException c)
            {
                System.out.println("Class not found");
                c.printStackTrace();
                return;
            }
          try {
                FileInputStream fis = new FileInputStream("students.ser");
                ObjectInputStream ois = new ObjectInputStream(fis);

                students =  (ArrayList<Student>) ois.readObject();

                ois.close();
                fis.close(); //serialize
            }
            catch (IOException ioe)
            {
                ioe.printStackTrace();
                return;
            }
            catch (ClassNotFoundException c)
            {
                System.out.println("Class not found");
                c.printStackTrace();
                return;
            }
        File ser = new File("courses.ser");
        if(!ser.exists()) {
            System.out.println("csv is currently not serialized, please run Serializer.java before running this");
        }
        Scanner input = new Scanner(System.in);
        System.out.print("Enter your username: ");
        String user = input.nextLine(); //prompt user and pass
        System.out.print("Enter your password: ");
        String pass = input.nextLine();

        for(Student stu: students) {
            if( user.equals(stu.username) && pass.equals(stu.password)) {
                System.out.println("Student login successfull\n");
                System.out.print("Enter a command: \n viewCourses, viewNotFull, register, withdraw, viewRegistered, or q to exit");
                String cmd = input.nextLine();
                while(!(cmd.equals("q"))) {
                    switch (cmd) {
                    case "viewCourses":
                        stu.viewCourses();
                        break;
                    case "viewNotFull":
                        stu.viewNotFull();
                        break;
                    case "register":
                        System.out.print("Enter the name of the course, the id, and your full name"); //first + last w space between
                        String name = input.nextLine();
                        int sec = input.nextInt();
                        String studentName = input.nextLine();
                        stu.register(name, sec, studentName);
                        break;
                    case "withdraw":
                        System.out.print("Provide your full name and the name of the course you wish to drop: ");
                        studentName = input.nextLine();
                        String courseName = input.nextLine();
                        stu.withdraw(studentName, courseName);
                    case "viewRegistered":
                        stu.viewRegistered();
                        break;
                    case "q":
                        break;
                    default:
                        System.out.print("Command not recognized");
                        break;

                    }
                    System.out.print("Enter a command: \n viewCourses, viewNotFull, register, withdraw, viewRegistered, or q to exit");
                    cmd = input.nextLine();
                }
                break;
            }
        }

        if(user.equals("Admin") && pass.equals("Admin001")) { //whether you're admin or not
            System.out.println("Administrator login successfull\n");
            Administrator a = new Administrator(courses, "admin", "admin", user, pass);
            System.out.print("Enter a command: \n createStudent, viewCourses, viewFull, writeFull, sort, createCourse, deleteCourse, registered\n courseInfo, or q to quit");
            String cmd = input.nextLine();
            while(!(cmd.equals("q"))) {
                switch (cmd) {
                case "createStudent":
                    System.out.print("Create a student, enter first name, last name, username, and password: ");
                    String f= input.nextLine();
                    String l = input.nextLine();
                    String u = input.nextLine();
                    String p = input.nextLine();
                    ArrayList<Course> n = null;
                    Student stuu = new Student(n,f,l,u,p);
                    students.add(stuu);
                    break;

                case "viewCourses":
                    a.viewCourses();
                    break;
                case "viewFull":
                    a.viewFull(); //implement all the methods for admin
                    break;
                case "writeFull":
                    try {
                        a.writeFull();
                    } catch (FileNotFoundException | UnsupportedEncodingException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                        System.out.println("Error");
                    }
                    break;
                case "sort":
                    a.sort();
                    break;
                case "createCourse":
                    String name;
                    String id;
                    int max;
                    int curr;
                    String ins;
                    int sec;
                    String loc;
                    System.out.print("Enter the course name, ID, max students, current students, instructor name, section number, and location: ");
                    name = input.nextLine();
                    id = input.nextLine();
                    max = Integer.parseInt(input.nextLine());
                    curr = Integer.parseInt(input.nextLine());
                    ins = input.nextLine();
                    sec = Integer.parseInt(input.nextLine());
                    loc = input.nextLine();
                    a.createCourse(name, id, max, curr, null, ins, sec, loc);
                    break;
                case "deleteCourse":
                    System.out.print("Enter a course name: ");
                    name = input.nextLine();
                    System.out.print("Enter a course id: ");
                    id = input.nextLine();
                    a.deleteCourse(name, id);
                    break;
                case "registered":
                    System.out.print("Enter the first name of the student: ");
                    f = input.nextLine();
                    System.out.print("Enter the last name of the student: ");
                    l = input.nextLine();
                    a.registered(f, l);
                    break;
                case "courseInfo":
                    System.out.print("Enter the course ID of the class you wish to get info on: ");
                    id = input.nextLine();
                    a.courseInfo(id);
                    break;
                case "q":
                    System.out.println("Quitting...");
                    break;
                default:
                    System.out.println("Command not recognized");
                    break;
                }

                System.out.print("Enter a command: ");
                cmd = input.nextLine();
            }
        }{
        FileOutputStream fileOutC = new FileOutputStream("courses.ser"); //start serializing courses
        ObjectOutputStream outC = new ObjectOutputStream(fileOutC);
        FileOutputStream fileOutS = new FileOutputStream("students.ser"); //start serializing students
        ObjectOutputStream outS = new ObjectOutputStream(fileOutS);
             try {
                 outC.writeObject(courses);
                 outS.writeObject(students);
              } catch (IOException i) {
                  i.printStackTrace(); //catch error
              }

             System.out.printf("Serialized data is saved in courses.ser and students.ser");
             outC.close();
             fileOutC.close();
             fileOutS.close();
             outS.close();
//          bufferedReader.close();
        }

    }

    }