求一java小程序 a到b之间的所有素数 结果保存到数据文件中

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
public class PrimeDemo {
public static void main(String[] args) {
System.out.println("Please enter two integers , separated or ended by RETURN:"); //请输入两个整数 以回车间隔或结束
Scanner in1 = new Scanner(System.in);
Scanner in2 = new Scanner(System.in);
int a = in1.nextInt();
int b = in2.nextInt();
String s="The primes between "+a+" and "+b+":\r\n"; //包含在a和b之间的素数为...
for (int i = a; i < b; i++) {
if (Primet.isPrime(i) && i != 1) {
System.out.println(i);
s=s+i+" ";
}
}
save(s);
}
static boolean isPrime(int n) { //求素数方法
for (int i = 2; i <= Math.sqrt(n); i++) {
if (n % i == 0) {
return false;
}
}
return true;
}
static void save(String s){ //保存方法
System.out.print