请问是哪里出错了？
package zh.codegym.task.task18.task1817;
import java.io.*;
import java.text.DecimalFormat;
/*
空格
*/
public class Solution {
public static void main(String[] args) throws Exception {
FileInputStream in = new FileInputStream(args[0]);
int n1 = 0, n2 = 0, n3 = 0;
while(in.available() > 0){
int data = in.read();
char ch = (char)data;
if(ch == 32){
n2++;
}
n1++;
}
in.close();
DecimalFormat df = new DecimalFormat("#.00");
double ratio = n2 / n1 * 100;
System.out.println(df.format(ratio));
}
}