Question

Hello I have a text file which I am trying to read a set of numbers from, this file looks similar to this:

st:ATTR1 20121011        0        0      127      122      -17

Im attempting to use a scanner, using the space as the delimiter, and read the first string, and the rest as ints. but whenever I try to run it I get this error:

Exception in thread "main" java.util.InputMismatchException
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 prog8.prog8.main(prog8.java:22)

Im not sure why this is, because as far as I’m aware this should just allow me to read the next int, without worrying about other characters.

My code is:

package prog8;

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

public class prog8 {

public static void main(String[] args) {
    File file = new File("files/Weather.txt");
    int date = 0;
    int prcp = 0;
    int snow = 0;
    int snwd = 0;
    int tmax = 0;
    int tmin = 0;

    try {
        Scanner reader = new Scanner(file).useDelimiter(" ");
        while (reader.hasNextLine()) {
            String station = reader.next();
            date = reader.nextInt();
            prcp = reader.nextInt();
            snow = reader.nextInt();
            snwd = reader.nextInt();
            tmax = reader.nextInt();
            tmin = reader.nextInt();
            System.out.printf("station: %s, date: %d, prcp: %d, snow: %d, snwd: %d, tmax: %d, tmin: %d", station, date, prcp, snow, snwd, tmax, tmin);

        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
}
}

can anyone tell me why this would be happening?

Answer 1

You can’t use multiple spaces if you’ve set the delimiter to be a single space.

Remove the .useDelimiter(" "); and your program works fine