Enter positive integers, one number per line, ending with -1
56    46    47    31    11
The sum of the numbers is 191
The average is 38.2

package javaapplication4;

import java.io.*;

public class JavaApplication4 {
    public static void main(String[] args) throws IOException{
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader keyboard = new BufferedReader(in);

        int num;
        int sum;
        int count;
        double average;

        System.out.println("Enter positive integers, one number per" +
        "line, ending with ..1");
        count = 0;
        sum = 0;
        num = Integer.parseInt(keyboard.readLine());

        while(num != -1){ sum = sum + num;
            count++;
            num = Integer.parseInt(keyboard.readLine());
        }
        System.out.println("The sum of the number is: " + sum);
        if(count !=0)
        average = sum / count;
        else
            average = 0;
        System.out.println("The average is: "+ average);
    }
}

Enter positive integers, one number perline, ending with ..1
 23 32
Exception in thread "main" java.lang.NumberFormatException: For input string: " 23 32"

Enter positive integers, one number perline, ending with ..1
5
6
-1
The sum of the number is: 11
The average is: 5.0

int sum = 0;
int count = 0;