Helpdesk APL

package nl.saxion.helpdesk;

import com.sun.org.apache.xml.internal.resolver.readers.ExtendedXMLCatalogReader;

import java.util.Scanner;

/**
 * APL for the helpdesk
 * You don't have to make any adjustments to this class
 * @author Evert Duipmans
 */
public class APL {
	public static void main(String[] args) {
		Helpdesk helpdesk = new Helpdesk();

		// Read all the data
		int numObjects = 0;
		try {
			numObjects = helpdesk.importData("i-desk.txt");
		} catch (HelpdeskException e) {
			System.err.println(e.getMessage());
		}
		System.out.println("Read: " + numObjects + " objects.");

		boolean closing = false;
		while (!closing) {
			System.out.println("");
			System.out.println("-----------");
			System.out.println("I-Desk");
			System.out.println("-----------");

			// User should first login
			if (!helpdesk.isLoggedOn()) {
				System.out.print("Please give your username: ");
				String inputUser = askString();
				System.out.print("Please give your password: ");
				String inputPassword = askString();
				if (!helpdesk.login(inputUser, inputPassword)) {
					System.out.println("ERROR: Cannot login user. Invalid credentials");
				}
			} else {
				// Show menu
				System.out.println("1. Add ticket");
				System.out.println("2. Resolve ticket");
				System.out.println("3. Show my tickets");
				System.out.println("4. Show open tickets");
                System.out.println("5. Show all tickets");
				System.out.println("6. Show users");
				System.out.println("7. Export data");
				System.out.println("8. Logout");
				System.out.println("9. Exit");
				System.out.println("");

				// Ask the user
				System.out.print("Choice: ");
				int choice = askNumber();
				System.out.println("-----------");

				// Process choice
				if (choice == 1) {
					System.out.println("Add ticket:");
					System.out.println("Please enter the type (hardware or software):");
					String type = askString();

                    while (!type.equalsIgnoreCase("hardware") && !type.equalsIgnoreCase("software")) {
                        type = askString();
                    }

					System.out.println("Please enter the description:");
					String description = askString();

                    if (type.equalsIgnoreCase("hardware")) {
                        System.out.println("Please enter the machineid:");
                        String machineId = askString();
                        int ticketNumber = helpdesk.addHardwareTicket(description, machineId);
                        System.out.println("New ticket is created with number: " + ticketNumber);
                    } else {
                        System.out.println("Please enter the software name:");
                        String softwareName = askString();
                        int ticketNumber = helpdesk.addSoftwareTicket(description, softwareName);
                        System.out.println("New ticket is created with number: " + ticketNumber);
                    }
				} else if (choice == 2) {
					System.out.println("Resolve ticket:");
					System.out.println("Please enter the ticket number:");
					int number = askNumber();
					System.out.println("Please enter the response:");
					String response = askString();

					try {
						helpdesk.resolveTicket(number, response);
					} catch (HelpdeskException e) {
						System.err.println(e.getMessage());
					}
				} else if (choice == 3) {
					System.out.println("Show my tickets:");
					helpdesk.printMyTickets();
				} else if (choice == 4) {
					System.out.println("Show open tickets:");
					try {
						helpdesk.printOpenTickets();
					} catch (HelpdeskException e) {
						System.err.println(e.getMessage());
					}
				} else if (choice == 5) {
					System.out.println("Show all tickets:");
					try {
                        helpdesk.printAllTickets();
					} catch (HelpdeskException e) {
						System.err.println(e.getMessage());
					}
				} else if (choice == 6) {
					System.out.println("Show all users:");
					try {
						helpdesk.printUsers();
					} catch (HelpdeskException e) {
						System.err.println(e.getMessage());
					}
				} else if (choice == 7) {
					System.out.println("Export data:");
					System.out.println("Please enter the filename:");
					String filename = askString();
					helpdesk.exportData(filename);
				} else if (choice == 8) {
					helpdesk.logout();
				} else if (choice == 9){
					closing = true;
				} else {
					System.out.println("Invalid choice.");
				}
			}
		}
	}

	/**
	 * Ask the user to enter a number. The system will ask the user again if incorrect input is provided by the user
	 * @return The entered number
	 */
	private static int askNumber() {
		int enteredNumber = -1;
		boolean askAgain = true;
		while (askAgain) {
			Scanner input = new Scanner(System.in);
			try {
				enteredNumber = Integer.parseInt(input.nextLine());
				askAgain = false;
			} catch (NumberFormatException e) {
				System.out.print("Error: Please enter a number.");
				askAgain = true;
			}
		}
		return enteredNumber;
	}

	/**
	 * Aks the user for a string. The system will ask again if invalid input is provided by the user
	 * @return The entered String
	 */
	public static String askString() {
		String enteredString = "";
		boolean askAgain = true;
		while (askAgain) {
			Scanner input = new Scanner(System.in);
			enteredString = input.nextLine();
			if (enteredString.length() != 0) {
				askAgain = false;
			} else {
				System.out.print("Error: Please enter at least one character.");
			}
		}
		return enteredString;
	}
}