Find max products

maxProduct.java

import java.util.Arrays;

class Scratch {
    public static int maxProduct(int[] numbers) {
        int length = numbers.length;
        if (length < 2) {
            throw new IllegalArgumentException(String.format("Require at least 2 numbers. But given: %s", Arrays.toString(numbers)));
        }

        int min1 = numbers[0];
        int min2 = Integer.MAX_VALUE;

        int max1 = numbers[0];
        int max2 = Integer.MIN_VALUE;

        for (int i = 1; i < numbers.length; i++) {
            if (numbers[i] < min1) {
                min2 = min1;
                min1 = numbers[i];
            } else if (numbers[i] < min2) {
                min2 = numbers[i];
            } else if (numbers[i] > max1) {
                max2 = numbers[i];
            } else if (numbers[i] > max2) {
                max2 = numbers[i];
            }
        }

        return Math.max((min1 * min2), (max1 * max2));

    }

    public static void main(String[] args) {
        int[] nums1 = {3, 2, 1, 4, 1};
        int[] nums2 = {3, 1, 4, 5, 2};
        int[] nums3 = {-1, -5, -4, 2, 5};

        System.out.println(maxProduct(nums1));
        System.out.println(maxProduct(nums2));
        System.out.println(maxProduct(nums3));

        // Should be error
        int[] errorNum1 = {2};
        System.out.println(maxProduct(errorNum1));
    }
}