Exception in java "java.util.InputMismatchException"

Question

So, I am working on a code for class and can't figure what is wrong. The code compiles and when I enter the file I'm searching for, I get this message:

Enter the name of the file: FanData.txt
Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:909)
    at java.util.Scanner.next(Scanner.java:1530)
    at java.util.Scanner.nextInt(Scanner.java:2160)
    at java.util.Scanner.nextInt(Scanner.java:2119)
    at FanDriver.fillArray(FanDriver.java:76)
    at FanDriver.main(FanDriver.java:35)

Press any key to continue . . .

I'm using TextPad as my compiler and the text file is in the project. The following is the code that I have written (ignore the methods being called in the quotes as they are something I need to do afterwards):

 import java.io.*;
import java.util.Scanner;

public class FanDriver
{
    private static Scanner keyboard = new Scanner(System.in);

    public static void main(String args[]) throws IOException
    {
        // Constant for the amount of elements of the array
        final int MAXSIZE = 100;

        // Declaring variables
        int amountFans = 0;

        // Declaring and initializing our array of fans
        Fan[] fans = new Fan[MAXSIZE];

        // Calling all of our methods
        amountFans = fillArray(fans, MAXSIZE);
/**
        listFanData(fans, amountFans);
        bubbleSortByAge(fans, amountFans);
        listFanData(fans, amountFans);
        bubbleSortByFan(fans, amountFans);
        listFanData(fans, amountFans);
        searchByAge(fans, amountFans);
        searchByFan(fans, amountFans);
*/

    }

    public static int fillArray(Fan[] array, int MAXSIZE) throws IOException
    {
        // Declaring variables
        int counter = 0;
        int age;
        String name;

        // Getting the file name
        System.out.print("\nEnter the name of the file: ");
        String fileName = keyboard.nextLine();

        // Opening the file
        File file = new File(fileName);
        Scanner inputFile = new Scanner(file);

        // Making sure the file was successfully opened
        if (!file.exists())
        {
            System.out.println("\nERROR: FILE DOESN'T EXIST. CLOSING PROGRAM NOW.");

            // Exiting the program
            System.exit(0);
        }

        // Reading all of the amounts from the file
        while (inputFile.hasNext() && counter < MAXSIZE)
        {
            name = inputFile.nextLine();
            age = inputFile.nextInt();

            array[counter] = new Fan(name, age);

            // Adding to our counter
            counter = counter + 1;
        }

        //Closing file
        inputFile.close();

        return counter;
    }
}

I do not have the code for the Fan class, just the class itself. The file we are retrieving is the file FanData.txt, which looks like this:

Chris P. Cream 5 Scott Free 9 Lou Tenant 3 Trish Fish 12 Ella Mentry 4 Holly Day 3 Robyn DeCradle 12 Annette Funicello 4 Elmo 7 Grover 3 Big Bird 9 Bert 7 Ernie 3 Grover 9

The text file is line-by-line. One line is a name and the next is a number. I don't know how to format it correctly on here. Any help would be greatly appreciated.

Answer 1

I am not sure about the delimiter in your input file.

The way you had instantiated your "Scanner"(without specifying any explicit delimiter) shall use default delimiter i.e. a whitespace character.

It seems that the "nextLine()" method in your case is not returning a "line".

It is rather returning a number or string(may be, you need check your file for that) which is not matching with the pattern followed by your Scanner.

Answer 2

The error is because of the type mismatch. After your first read scanner will be pointing to a non Integer value.

try to print your name before doing

age = inputFile.nextInt();

you will get to know the issue.

Above mentioned are means to understand the mistake.

Solution for your problem

Try :

age = Integer.parseInt(inputFile.nextLine()); // instead of age = inputFile.nextInt();

Answer 3

Exception is because of type mismatch as you are reading a text value from textfile and directly assigning to an int type.

Exception will be resolved if you parse the value as an integer as below

Integer.valueOf(inputFile.nextLine());