质数prime numbers

public class PrimeDemo {
public static void main(String[] args) {
int num = 100;
System.out.println(num + "以内的质数：");
getPrime(num);
}

// 获取max以内全部质数
public static void getPrime(int max) {
if (max < 2) return;
for (int i = 2; i <= max; i++) {
boolean isPrime = true;
for (int j = 2; j <= Math.sqrt(i); j++) {
if (i % j == 0) {
isPrime = false;
break;
}
}
if (isPrime) System.out.print(i + " ");
}
}
}