java之判断输入的数是否为素数

import java.util.Scanner;

public class TestIsSushu {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("输入正整数：");
int i = scan.nextInt();
if(i<0) {
System.out.println("输入错误！");
}else if(i==1||i==0) {
System.out.println(i+"既非素数也非合数");
}else {
boolean isSushu = true;//标记
for(int j=2;j<i;j++) {
if(i%j==0) {
isSushu = false;
break;
}
}
if(isSushu==true) {
System.out.println(i+"是素数");
}else {
System.out.println(i+"不是素数");
}
}
}
}