Java程序读取文本文件csb.txt统计字符数量并将结果保存到result.txt

 package Test;

    
  
    
 import java.io.*;
    
 import java.util.HashMap;
    
 import java.util.Map;
    
 import java.util.Set;
    
  
    
 /*
    
 读取文本文件csb.txt,统计字符个数,并把结果保存到result.txt
    
  */
    
 public class Test05 {
    
     public static void main(String[] args) throws Exception {
    
     BufferedReader br = new BufferedReader(new FileReader("D:/csb.txt"));
    
     BufferedWriter bw = new BufferedWriter(new FileWriter("D:/res.txt"));
    
     String str = "";
    
     String res = "";
    
     while((str