This example uses the standard Java API classes:

    1   import java.util.Scanner;
    2   
    3   public class AverageX {
    4   
    5     public static void main(String[] args) {
    6   
    7       Scanner stdin = new Scanner(System.in);
    8   
    9       int count = 0;       // number input values
   10       double sum = 0.0;    // sum of input values
   11   
   12       // read data and compute statistics
   13       while (stdin.hasNextDouble()) {
   14         double value = stdin.readDouble();
   15         sum += value;
   16         count++;
   17       }
   18   
   19       // compute the average
   20       double average = sum / count;
   21   
   22       // print results
   23       System.out.println("Average is " + average);
   24     }
   25   }