使用Excel编辑csv文件，而无需在android中重新格式化

Question

我正在尝试创建一个简单的Android应用程序，基本上导入csv并将其插入自定义的数组列表。到目前为止，当我没有更新CSV文件内容时，我能够读取csv文件。当我用excel更新CSV文件时，我发现它改变了csv文件的格式。
       这是我读取csv文件的代码：

     selectedFile = new File(data.getStringExtra(FilePicker.EXTRA_FILE_PATH));
         ArrayList<Expense> objList= new ArrayList<>();
       String file=selectedFile.getPath();

      FileInputStream fileInputStream = null;
      try {
             fileInputStream = new FileInputStream(new File(selectedFile.getPath()));
           } catch (FileNotFoundException e) {
                   e.printStackTrace();
                        }


        BufferedReader reader = null;
     reader = new BufferedReader(new InputStreamReader(fileInputStream, Charset.forName("UTF-8")));

             String line = "";
                        StringTokenizer st = null;
                        try {

                            while ((line = reader.readLine()) != null) {
                                st = new StringTokenizer(line, ",");
                                ExpenseShare obj= new ExpenseShare ();
                                //your attributes
                                obj.setAmount(st.nextToken());
                                obj.setName(st.nextToken());
                                obj.setDate(st.nextToken());
                                obj.setTime(st.nextToken());
                                objList.add(obj);

                                Log.e("latasingh"," "+obj.getName()+" "+(obj.getAmount())+" "+obj.getDate()+" "+ obj.getTime()); //I understood this problem by seeing log data.
                            }
                        } catch (IOException e) {

                            e.printStackTrace();
                        }

我该如何解决这个问题。 谢谢!!