如何将结果打印到txt文件？

Question

我尝试将所有pr.prinln（在代码底部）打印到屏幕上显示的result.txt，但是;当我运行代码时，生成result.txt但在正文中保持为空。请帮忙！

import java.io.*;
public class Assignment8
 {
public static void main(String[] args)
{
try {
//create an InputStreamReader obj first
InputStreamReader ir = new InputStreamReader(System.in);
File outf=new File("result.txt");
PrintWriter pr = new PrintWriter(outf);

//create a BufferedReader obj
BufferedReader br = new BufferedReader(ir);

//variales
double b,a,d,w, interest;
int count =0;
double sumd =0.00;
double sumw =0.00;
double sumi =0.00;
double totalI;//format

System.out.print("\nEnter the starting balance on the account: $");
b = Double.parseDouble(br.readLine());

System.out.print("\nEnter the annual interest rate on the account (e.g. .04): ");
a = Double.parseDouble(br.readLine());

for(int i=1; i<4; i++)
{
    count++;

    //#3 read in the next data
    System.out.print("\nMonth"+i);
    System.out.print("\nTotal deposits for this month: $");
        d = Double.parseDouble(br.readLine());
        sumd += d;
    System.out.print("Total withdrawals for this month: $");
        w = Double.parseDouble(br.readLine());
        sumw += w;
        interest = b+(b+d-w)*a/12-b;
        sumi +=interest;

}
totalI=+b+sumd-sumw+sumi;

System.out.println("\nQuarterly Savings Account Statement");
System.out.println("\nStarting balance:    $ "+b);
System.out.println("Total deposits:    + $ "+sumd);
System.out.println("Total withdrawals: - $ "+sumw);
System.out.println("Total interest:    + $   "+sumi);
System.out.println(" ----------- ");
System.out.println("Ending balance:      $ "+totalI);


pr.println("\nQuarterly Savings Account Statement");
pr.println("\nStarting balance:    $ "+b);
pr.println("Total deposits:    + $ "+sumd);
pr.println("Total withdrawals: - $ "+sumw);
pr.println("Total interest:    + $   "+sumi);
pr.println(" ----------- ");
pr.println("Ending balance:      $ "+totalI);

//double d = 3.14159;
//printf ("%.2f", d);

}
catch (IOException e)
{
System.out.println(e);
}
catch (ArithmeticException e)
{
    System.out.println("Wrong, restart!");
}
}

}