What path does “getApplicationContext().getFilesDir()” return?

Question

I\'m doing a simple app in Android and in a certain part of the app I would like to create an Excel file and write in it. I\'ve already prepared everything to use jexcel lib

Answer 1

If you want to access your file via your PC (with an usb cable) or via a file manager on your device, prefer:

new File(getExternalFilesDir(null), fileName);

This folder is created in .../Android/data/ ... com.yoursociety.yourapp/files ...

null means that you do not want to store files in predefined folders like Movies, Pictures and so on.

(See documentation for more info)

Answer 2

This worked:

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context = getApplicationContext();
        b = (Brain)load("brain.txt");
        if (b == null) {
            b = new Brain();
        }
        vocabulary = (ArrayList <String>) load("vocabulary.txt");
        if (vocabulary == null) {
            vocabulary = new ArrayList <String> ();
            vocabulary.add("I love you.");
            vocabulary.add("Hi!");
        }
        b.setRunning(true);
    }

public Object load(String fileName) {
    File file = new File("/storage/emulated/0/Android/data/com.cobalttechnology.myfirstapplication/files/" + fileName);
    if (!file.exists()) {
        return null;
    }
    try {
        Object o;
        FileInputStream fis = new FileInputStream(file);
        ObjectInputStream ois = new ObjectInputStream(fis);
        o = ois.readObject();
        if (o == null) {
            System.out.println(fileName + " = null");
        }
        ois.close();
        fis.close();
        System.out.println("Loaded: " + fileName);
        return o;
    } catch (IOException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException cnfe) {
        cnfe.printStackTrace();
    }
    return null;
}
public void save(Object o, String fileName) {
    File file = new File("/storage/emulated/0/Android/data/com.cobalttechnology.myfirstapplication/files/" + fileName);
    try {
        if (!file.exists()) {
            file.createNewFile();
        }
        FileOutputStream fos = new FileOutputStream(file);
        ObjectOutputStream oos = new ObjectOutputStream(fos);
        oos.writeObject(o);
        oos.close();
        fos.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Answer 3

Read the documentation, this method reads the files stored in the internal storage that were created with with openFileOutput():

getFilesDir()

Returns the absolute path to the directory on the filesystem where files created with openFileOutput(String, int) are stored.

Answer 4

On Android KitKat, it returns /data/data/{your package name}/files, however I imagine this could change depending on your platform version. Thus if you're just trying to dig through your filesystem and see a file, it's safe to use this path, but if you're using this path for some functionality across multiple platform versions, you should only reference it using getFilesDir().

Answer 5

What are you planning on using this file for? Do you want it usable by other apps too? Using getApplicationContext().getFilesDir() will give you /data/data/com.package/files but if you want a file that's easily accessible by yourself and other apps, you're better off using something like getExternalFilesDir()