将txt文档中的字符串中两个相邻的逗号替换成一个逗号

讲真的很菜

package com.eedu.test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;

public class ReplaceString {
    
    public static void main(String[] args) throws Exception {
        
        String str;
        BufferedReader bf = new BufferedReader(new FileReader(new File("C:\\Users\\Administrator\\Desktop\\rating.txt")));
        BufferedWriter out = new BufferedWriter(new FileWriter(new File("C:\\Users\\Administrator\\Desktop\\copyRating.txt")));
        
        while ((str = bf.readLine()) != null) {
            str = str.replace(",,",",");
            str = str+"\n";
            out.write(str);
        }
        out.flush();
        out.close();
        bf.close();

    }

}