prime number between two numbers in java

1public class Prime {
2
3    public static void main(String[] args) {
4
5        int low = 20, high = 50;
6
7        while (low < high) {
8            boolean flag = false;
9
10            for(int i = 2; i <= low/2; ++i) {
11                // condition for nonprime number
12                if(low % i == 0) {
13                    flag = true;
14                    break;
15                }
16            }
17
18            if (!flag && low != 0 && low != 1)
19                System.out.print(low + " ");
20
21            ++low;
22        }
23    }
24}