Code for finding all prime number under a given number N

I will be using the Sieve of Eratosthenes algorithm as mentioned on the wiki.

The code is like this:

import java.util.Arrays;
import java.util.Scanner;

public class FindingPrime {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int n = Integer.parseInt(scanner.nextLine());

        boolean[] a = new boolean[n];
        Arrays.fill(a, true);

        int squareRoot = (int) Math.ceil(Math.sqrt(n));

        for (int i = 2; i < squareRoot; i++) {
            if (a[i]) {
                int square = i * i;
                for (int j = square; j < n; j = (j + i)) {
                    a[j] = false;
                }
            }
        }

        for (int i = 2; i < a.length; i++) {
            if (a[i]) {
                System.out.print(i + " ");
            }
        }
    }
}