更改或删除移动存储中文件txt中的单行

Question

I'm developing an application for save more accounts. I don't use database but i use file... My question is if is possible change or delete a single row in the file txt on the storage of my phone???

Answer 1

You can edit a file only if you have read and write access to it. You mentioned in the comments that you have already read and written to a file. To edit what you have to do is read the content from the file, edit it and write it again. To achieve that just repeat what you did when reading/writing to it

To edit a file's content, you need to read it from disk, create a new FileInputStream with it, edit your stream then create a new FileOutPutSteam and write to it, like below:

File file = f;
FileInputStream fin;
fin = new FileInputStream(file);
byte fileContent[] = new byte[(int)file.length()];
fin.read(fileContent)
//Convert your stream to string, manipulate it and convert it back to a stream
FileOutputStream fos = new FileOutputStream(f.getAbsolutePath());
fos.write(my_out_stream);
fin.close();
fos.close();

To convert your FileInputStream to a string use: https://stackoverflow.com/a/15161590/10089348

And to convert back it to a FileOutputStream use https://stackoverflow.com/a/4069932/10089348

Hope it helps :)