java - nextDouble() throws an InputMismatchException when I enter a double

import java.util.*;

class Averager
{
    public static double unlimited()
    {
        int count = 0;
        double sum = 0;
        Scanner scan = new Scanner(System.in);
        while(scan.hasNext())
        {
            double d = scan.nextDouble();
            sum += d;
            count++;
        }
        double ave = sum/count;
        return ave;
    }

    public static void main(String[] args) {
        System.out.println(unlimited()+"\n");
    }
}

There is no error when I use integers but if I use numbers with point in it a error appears.

$ javac Averager.java; java Averager
0.5
Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:840)
    at java.util.Scanner.next(Scanner.java:1461)
    at java.util.Scanner.nextDouble(Scanner.java:2387)
    at Averager.unlimited(Averager.java:12)
    at Averager.main(Averager.java:21)

To my best understanding 0.5 should be covered by double. If not please can someone correct me.

Answer

It might be locale dependent. Decimal numbers are e.g written as 0,5 in Sweden.

Change your code so that it says e.g.:

Scanner scan = new Scanner(System.in);
scan.useLocale(Locale.US);