Uitzondering in thread “main” java.util.NoSuchElementException: geen regel gevonden

Ik probeer gebruikersinvoer te krijgen en na de 2e invoerwaarde krijg ik deze foutmelding:

Uitzondering in thread “main” java.util.NoSuchElementException: Geen regel gevonden
op java.util.Scanner.nextLine (onbekende bron)
op Reserveringen.start(Reservaties.java:50)
op Reservations.main(Reservations.java:29)

import java.util.Scanner; // Needed to read user input
public class Reservations {
        // Boolean array for seating [false = available, true = taken]
        static boolean[][] seats;
        // Main method
        public static void main(String[] args) {
                // Initiates all array values to be false (available)
                seats = new boolean[4][4];
                for (int i = 0; i < 4; i++) {
                        for (int j = 0; j < 4; j++) {
                                seats[i][j] = false;
                        }
                        // Welcome message
                        System.out.println("-------------------------");
                        System.out.println("Welcome to NSCC AirLines.");
                        System.out.println("-------------------------\n");
                        // Starts program
                        start();
                }
        }
        public static void start() {
                // Scanner needed to read users input
                Scanner sc = new Scanner(System.in);
                // Variables for user input
                String requestedSection;
                String requestedSeat;
                // Counters for seating array
                int countSection = 0;
                int countSeat = 0;
                // Prompts the user to select their choice of section
                System.out.print("Please type 1 for First Class or 2 for Economy: ");
                // Section preference
                requestedSection = sc.nextLine();
                switch (requestedSection) {
                case "1":
                        // User selects first class
                        System.out.println(">>> You have selected First Class. \n");
                        break;
                case "2":
                        // User selects economy
                        System.out.println(">>> You have selected Economy. \n");
                        break;
                default:
                        // User has not selected a valid class
                        System.out
                                        .println(">>> You have not selected a valid class. Please try again. \n");
                        start();
                        break;
                }
                // Prompts the user to select their choice of seat
                System.out.print("Please type 1 for window and 2 for aisle: ");
                // Seat preference
                requestedSeat = sc.nextLine();
                switch (requestedSeat) {
                case "1":
                        // User selects first class
                        System.out.println(">>> You have selected a window seat. \n");
                        break;
                case "2":
                        // User selects economy
                        System.out.println(">>> You have selected an aisle seat. \n");
                        break;
                default:
                        // User has not selected a valid class
                        System.out.println(">>> You have not selected a valid seat. Please try again. \n");
                        start();
                        break;
                }
                // Closes Scanner
                sc.close();
        }
}

Antwoord 1, Autoriteit 100%

Het API-document van Readline () -methode zegt zoals hieronder

Throws:
    NoSuchElementException - if no line was found 

U moet deze uitzondering verwerken of gebruik gewoon de hasnextline () -methode om de uitzondering te voorkomen.

while(sc.hasNextLine()){
    requestedSeat = sc.nextLine();
}