package Homework3;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

/**
* The driver class for this project.
*/
public class Main {
// the private members of this class
private static File file;
private static Scanner scanner;
private static Scanner sc;

// initialize arrays to store the different class objects
private static Doctor[] doctors = new Doctor[10];
private static Nurse[] nurses = new Nurse[10];
private static Surgeon[] surgeons = new Surgeon[10];
private static Janitor[] janitors = new Janitor[10];
private static Receptionist[] receptionists = new Receptionist[10];
private static Administrator[] administrators = new Administrator[10];
private static HospitalEmployee[] hospitalEmployees = new HospitalEmployee[10];
private static int numberOfDoctors = 0;
private static int numberOfNurses = 0;
private static int numberOfSurgeons = 0;
private static int numberOfJanitors = 0;
private static int numberOfReceptionists = 0;
private static int numberOfAdministrators = 0;
private static int numberOfHospitalEmployees = 0;

/**
* The main entry point method for this class
* @param args: the command-line arguments, if any.
*/
public static void main(String[] args) {
   // load data from the database into the respective arrays
   loadDatabase();

   // now, create a while loop displaying the menu
   // this variable tracks whether or not uses chooses to quit.
   boolean quitMenu = false;
   // create Scanner object to take user input
   sc = new Scanner(System.in);
   System.out.println("***********************************");
   System.out.println("Welcome to the UAB Employee System");
   System.out.println("***********************************");
   while (!quitMenu) {
         System.out.println("Please choose your option:\n" +
               "1 - Display the employee list\n" +
               "2 - Add employee\n" +
               "3 - Update the database\n" +
               "4 - Delete employee\n" +
               "5 - Quit\n>>> ");
         // get user input
         String userInput = sc.nextLine();
         switch (userInput) {
            case "1":
               // display employee list
               displayInformation();
               break;
            case "2":
               // invoke method that adds new employee
               addEmployee();
               break;
            case "3":
               // invoke method that updates database
               updateDatabase();
               break;
            case "4":
               // invoke method that deletes an employee
               deleteEmployee();
               break;
            case "5":
               // quit the while loop and display information to the user
               quitMenu = true;
               System.out.println("Quitting the application...");
               break;
            default:
               // if an invalid option is entered, inform the user
               System.out.println("Invalid Option!");
               break;
         }
   }
}

/**
* This method updates the database file with the latest changes.
* It writes each element of all the object arrays in the specified format
*/
private static void updateDatabase() {
   try {
         FileWriter writer = new FileWriter("uabEmployee.txt");
         // iterate through the elements in each object array, and write the information
         // onto the file
         // hospital employees
         for (int i = 0; i < numberOfHospitalEmployees; i++) {
            String statement = String.format("E %s %d\n", hospitalEmployees[i].name, hospitalEmployees[i].blazerId);
            writer.write(statement);
         }

         // doctors
         for (int i = 0; i < numberOfDoctors; i++) {
            String statement = String.format("D %s %d %s\n", doctors[i].name,
                     doctors[i].blazerId, doctors[i].speciality);
            writer.write(statement);
         }

         // surgeons
         for (int i = 0; i < numberOfSurgeons; i++) {
            String statement = String.format("S %s %d %s %s\n", surgeons[i].name,
                     surgeons[i].blazerId, surgeons[i].speciality, surgeons[i].operating);
            writer.write(statement);
         }

         // nurses
         for (int i = 0; i < numberOfNurses; i++) {
            String statement = String.format("N %s %d %d\n", nurses[i].name,
                     nurses[i].blazerId, nurses[i].numberOfPatients);
            writer.write(statement);
         }

In this part 3, you re-use the prior part 2 which re-uses the prior...