Week 7: Enum, Generic Type, Streams, write to file, class diagram/09B. Sum, Average, Minimum, Maximum+++

Write a program that asks the 'user to enter integers'. 
The program stores the numbers in a 'list of integers'.

When the user enters the 'number -1', the program execution 'ends', 
and it prints the sum, average, minimum, and maximum of all the numbers entered (before -1).


Use streams to calculate the values!




Example execution:
Enter a number: 1
Enter a number: 2
Enter a number: 3
Enter a number: -1
Sum: 6
Average: 2.0
Minimum: 1
Maximum: 3



    
import java.util.Random;
import java.util.ArrayList;
import java.util.Scanner;



public class Test {
    public static void main(String[] args) {
        final Random r = new Random();
        

    // ADD
    // USER INPUTS INTEGERS
    ArrayList<Integer> numbers = new ArrayList<>();
    Scanner reader = new Scanner(System.in);
    while (true) {
        System.out.print("Give a number: ");
        int number = Integer.valueOf(reader.nextLine());

        if (number == -1) {
            break;
        }
        numbers.add(number);
    }
    

    // SUM AVG MIN MAX
    if (!numbers.isEmpty()) {
        // sum() method returns an int, so no need to getAsInt()
        System.out.println("Sum: " + numbers.stream().mapToInt(num -> num).sum());
        System.out.println("Average: " + numbers.stream().mapToInt(num -> num).average().getAsDouble());
        System.out.println("Minimum: " + numbers.stream().mapToInt(num -> num).min().getAsInt());
        System.out.println("Maximum: " + numbers.stream().mapToInt(num -> num).max().getAsInt());
    }
}



Test number 1
Give a number: 2
Give a number: 3
Give a number: 4
Give a number: 5
Give a number: -1
Sum: 14
Average: 3.5
Minimum: 2
Maximum: 5

Test number 2
Give a number: 10
Give a number: 12
Give a number: 14
Give a number: 16
Give a number: -1
Sum: 52
Average: 13.0
Minimum: 10
Maximum: 16

Test number 3
Give a number: 9
Give a number: 7
Give a number: 5
Give a number: 3
Give a number: -1
Sum: 24
Average: 6.0
Minimum: 3
Maximum: 9

Test number 4
Give a number: 100
Give a number: 103
Give a number: 107
Give a number: 99
Give a number: -1
Sum: 409
Average: 102.25
Minimum: 99
Maximum: 107