如何使用Android内部存储

Question

I am writing an application where I would like to allow the created csv file to be used on a PC. Android has Internal Storage which is viewable on the Android and can be accessed via USB on the PC. I tried various methods to generate a file name:

/data/user/0/com.ed.ilan.ioioterbium/files/documents/2016_9_16_10_28_12.csv
/data/user/0/com.ed.ilan.ioioterbium/files/2016_9_16_10_35_57.csv
2016_9_16_10_46_34.csv

The name of the application I got using getFilesDir(), but the first 2 examples didn't work as Java complained about the slashes in the name. The 3rd one worked but nothing was visible in (appName)/files/. I don't know if this by design for security reasons, or if the file was really not there. The code is

String name = getFileName();
try {
        FileOutputStream fOut = new FileOutputStream(name);
        OutputStreamWriter osw = new OutputStreamWriter(fOut);
        osw.write("test1");
        osw.flush();
        osw.close();
        fOut.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

Where I would really like the file to be would be in Internal Storage. I created a folder called myData, which I can see both on the phone and on the PC. The question is: how do I direct the application to write to Internal Storage. I recognize that this isn't "secure", but I just want to get the file.

To write to the Internal storage one needs this in the manifest

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

If we should decide to put the file on a cloud server, is there a standard way to do that?

Thanks, Ilan

Answer 1

I understand that you want to write a file to your phone's Documents folder, am I right? If so, the following may be of help where you can write your .csv files at.

 Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS);

Answer 2

If you are using getFilesDir() then it returns a path which is specific to android application. User's simply can't access the path returned by getFilesDir().

If you have a rooted device then you can get access to the above path.

If you want that only your application can access files stored by you then use getFilesDir() , else you can use

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS).getAbsolutePath();