判断质数的快捷方法

import java.util.Scanner;

public class PrimeNumber {

static boolean primeNumber(int i){
if(i==2||i==3)
return true;
int mul = 1;
for(int m=i-2;m>1;m--){
mul = mul *m;
}
if((mul%i)==1)
return true;
else
return false;
}
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int i = s.nextInt();
System.out.println(primeNumber(i));
}

}