I have an app that saves into a file (internal storage) data input by the user and at startup it loads this file and shows the contents. I would like to know: where can I find my file (data.txt)?
In addition, if I input "Hello" and then "World" when I load the file, I see "HelloWorld" in the same line but I want "Hello" and "World" printed on two different lines.
For saving file:
public void writeToFile(String data) {
    try {
        FileOutputStream fou = openFileOutput("data.txt", MODE_APPEND);
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fou);
        outputStreamWriter.write(data);
        outputStreamWriter.close();
    }
    catch (IOException e) {
        Log.e("Exception", "File write failed: " + e.toString());
    }
}
For loading file:
public String readFromFile() {
    String ret = "";
    try {
        InputStream inputStream = openFileInput("data.txt");
        if ( inputStream != null ) {
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String receiveString = "";
            StringBuilder stringBuilder = new StringBuilder();
            while ( (receiveString = bufferedReader.readLine()) != null ) {
                stringBuilder.append(receiveString);
            }
            inputStream.close();
            ret = stringBuilder.toString();
        }
    }
    catch (FileNotFoundException e) {
        Log.e("login activity", "File not found: " + e.toString());
    } catch (IOException e) {
        Log.e("login activity", "Can not read file: " + e.toString());
    }
    return ret;
}
Thanks.
[UPDATE]
I've inserted "\n" after every input:
user = (EditText) v.findViewById(R.id.username);
writeToFile(user.getText().toString() + "\n");
But when I print my file, they are always on the same line.
Where can I find my file (data.txt)?
You can find the path of the directory, which is created by openFileOutput, by using YourActivity.this.getFilesDir().getAbsolutePath().
But I want "Hello" and "World" printed in two different lines.
Use line.separator after writing a word in a file, for example:
String separator = System.getProperty("line.separator");
outputStreamWriter.write(data);
outputStreamWriter.append(separator);
...
Or you can also use replaceAll to break String into multiple lines:
String separator = System.getProperty("line.separator");
data=data.replaceAll(" ",separator);
    I guess you can find it here: data/data/[your package name]/... and regarding writing in two separate lines just add "\n" whenever you need to go to another line.
来源:https://stackoverflow.com/questions/27819100/android-fileoutputstream-location-save-file