判断一个数是否是素数

package com.test1;

import java.util.Scanner;
import java.math.*;

public class test8 {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

Test t = new Test();
t.play();

}

}

class Test {
public void play() {
System.out.println("请输入数字");
Scanner s = new Scanner(System.in);
int m = s.nextInt();

int k = (int) Math.sqrt(m);
int i = 2;
// System.out.println(number);
for (i = 2; i <= k; i++) {
if (m % i == 0) {
break;
}
}

if (i > k) {
System.out.println("是素数");
} else

{
System.out.println("不是素数");
}

}
}