Question

I wrote a function that scans a tab delimited file of baseball stats.

public static ArrayList dataRead() throws FileNotFoundException {
    //ArrayList array = new ArrayList<ArrayList>();
    Scanner s = new Scanner(new File("c:\\stats.txt")).useDelimiter("\r");

    ArrayList<String> array = new ArrayList<String>();
    int i = 0;
    while(s.next() != null) {
        String currentLine = s.next();
        Scanner split = new Scanner(currentLine).useDelimiter("\t");
        for(int j = 0; j < 16; j++) {
            System.out.print(split.next() + " ");

            j++;

        }
        System.out.println("\r");
    }
    s.close();
    return array;
}

This function works until the end of the file. To my knowledge the while loop should close at the end of the file because it returns null, but I keep getting a noSuchElement error instead. If I could guarantee the file size, I would just use a for loop with the size, but I can’t because team size could technically vary. How would I properly end the file scanner while loop so I can close the scanner?

Answer 1

From: Javadocs for Scanner.next()

Throws:
NoSuchElementException – if no more tokens are available

When there are no more lines left in the file, calling s.next() throws a NoSuchElementException exception. You’re also calling s.next() twice, once in the while() and once inside the loop. You should really be called while(s.hasNext()) instead.