如何书写判断素数的判断条件

import java.util.Scanner;
public class Test40013 {
public static void main(String args[]) {
int ri, repeat;
int i, m, n;
boolean flag;
Scanner in = new Scanner(System.in);
repeat = in.nextInt();
for** (ri = 1; ri <= repeat; ri++) {
m = in.nextInt();
/--------------------/
flag = true;
if (m == 1)
flag = false;
else {
i = 2;
flag = true;
while (i < m && flag) {
if (m % i == 0)
flag = false;
i++;
}
}
if (flag)
System.out.println("YES");
else
System.out.println("NO");
}
}

}
后边的if条件看不懂