Approach 1

import java.util.Arrays;
import java.util.List;

public class SumOfNumbers {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(3, 5, 7, 2, 8);

        // Using Stream and mapToInt with sum()
        int sum = numbers.stream()
                         .mapToInt(Integer::intValue)
                         .sum();

        System.out.println("Sum of all numbers: " + sum);
    }
}

Approach 2

import java.util.Arrays;
import java.util.List;

public class SumUsingReduce {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(3, 5, 7, 2, 8);

        // Using reduce method
        int sum = numbers.stream()
                         .reduce(0, (a, b) -> a + b);

        System.out.println("Sum of all numbers: " + sum);
    }
}