Java Scanner exception from unknown source during File I/O

Question

I am trying to play around with opening, closing, and writing to files. Whenever I try to open a file, if it doesn't exist at the path I provide the program tells me. If it exists, the program reads whatever is inside and displays it. If the user doesn't want to look for a file, there is an option to create a file and fill it with data.

It works so far except whenever I read a file, after it is successful in displaying the data I get an unknown source Scanner exception. Here is my code so far:

import java.util.Scanner;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;

public class FileIO {
    public static void main(String[] args) throws IOException{

        Scanner input = new Scanner(System.in);

        while (true){

            System.out.println("1. Load file from path of your choosing.");
            System.out.println("2. Answer eight questions and save the answers into a file.");
            System.out.println("3. Exit the program.");


            int userChoice = input.nextInt();

            switch (userChoice){
            case 1:
                loadFile();
                break;
            case 2:
                answerQuestions();
                break;
            case 3:
                System.out.println("Goodbye!");
                break;
            }
        }
    }

    public static void loadFile() throws IOException{
        System.out.println("What is the file name you want to try to read?");
        Scanner input = new Scanner(System.in);
        File f = new File(input.nextLine());
        if (f.exists() && !f.isDirectory()){
            System.out.println("The file exists!");
            Scanner inputFile = new Scanner(f);
            while (inputFile.hasNext()){
                String answer = inputFile.next();
                System.out.println(answer);
            }

            input.close();
        }
        else {
            System.out.println("File does not exist at that given path!");
        }

    }

    public static void answerQuestions() throws IOException{

        Scanner input = new Scanner(System.in);
        System.out.println("What is your name?"); // 1
        String name = input.nextLine();
        System.out.println("What is your favorite color?"); // 2
        String color = input.nextLine();
        System.out.println("What is your favorite type of music?"); // 3
        String music = input.nextLine();
        System.out.println("What is your favorite place?"); // 4
        String place = input.nextLine();
        System.out.println("What is your favorite food?"); // 5
        String food = input.nextLine();
        System.out.println("What is your favorite book?"); // 6
        String book = input.nextLine();
        System.out.println("What is your favorite programming language?"); // 7
        String language = input.nextLine();
        System.out.println("Do you prefer laptop or desktop computers?"); // 8
        String computer = input.nextLine();

        System.out.println("All the questions are answered. Name the file you want to save the answers to: ");
        File f = new File(input.nextLine());
        if (f.exists()){
            System.out.println("File already exists!");
            return;
        }
        PrintWriter output = new PrintWriter(f);
        output.print(name + "\n");
        output.print(color + "\n");
        output.print(music + "\n");
        output.print(place + "\n");
        output.print(food + "\n");
        output.print(book + "\n");
        output.print(language + "\n");
        output.print(computer + "\n");

        output.close();

    }
}

This is the error:

Exception in thread "main" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at Lab4.main(Lab4.java:18)

What exactly is the problem? I tried changing the Scanner input on line 19 to input2 but that didn't work. The program lets me select as many menu options as I want if the file does not exist when checking a path, so I'm guessing something is wrong with the program at the part where it starts printing stuff to the console if a file is found. But I have no idea what it could be. I would appreciate any tips or hints that guide me towards handling this error. Thanks for your time.

Answer 1

Remove input.close(); from loadFile() function as it is closing referenced standard input stream blocking further IO.

Answer 2

Scanner input = new Scanner(System.in);
/* other code here */
input.close();

Closing a Scanner also closes the stream it's using. You closed System.in. Just like any other stream, if it's closed, you can't use it.

The ideal solution would be to create a Scanner once (at the start of the program) and then use it every time you want to read input.