Where to put a file in android so it can be opened?

Question

I want to open a file in android using the following code:

 FileInputStream fis = openFileInput("examplelist.txt");
 InputStreamReader isr = new InputStreamReader(fis);
 BufferedReader bufferedReader = new BufferedReader(isr);
 StringBuilder sb = new StringBuilder();
 String line;
 while ((line = bufferedReader.readLine()) != null) {
     sb.append(line);
 }

but where to put the file examplelist.txt? I found some contradicting sources, like this and this? How to do it correctly?

Update:

I want to be able to replace this file at anytime after the app has been installed. So this file is NOT part of the source code or anything. It contains dynamical data...

I would have used a simple 'File Selector', so the user can navigate to the file anywhere on the android phone, but this looks terribly complicated and cumbersome. So, for now, I just want to open a file I can put somewhere on the phone in the most possible simple manner...

Answer 1

In order to be able to access a file, you should place it in /app/src/main/assets/examplelist.txt. You can access this directory in the Project explorer in Android Studio.

To open the file from java code, you can create an InputStream object by calling getAssets().open("examplelist.txt")

Answer 2

One possible way to solve this problem is the following:

1. You put the file in the kind-of-root folder, which might have the following path: /storage/emulated/0 (this is the location you can see when you connect the device e.g. to Linux and open it in the file explorer).

2. You can open the content of the file using the following code:

   String path = Environment.getExternalStorageDirectory().toString();
   Log.d("Files", "Path: " + path);
   
   String joinedPath = new File(path, "examplelist.txt").toString();
   try {
       FileInputStream fis =new FileInputStream(new File(joinedPath));
       InputStreamReader isr = new InputStreamReader(fis);
       BufferedReader bufferedReader = new BufferedReader(isr);
       StringBuilder sb = new StringBuilder();
       String line;
       while ((line = bufferedReader.readLine()) != null) {
           sb.append(line);
       }
       Log.d("Text", sb.toString());
    } catch (IOException e) {
       Toast.makeText(getBaseContext(), "File does not exist", Toast.LENGTH_LONG).show();
    }
   

3. VERY IMPORTANT, and which I forget EVERY single time: You have to set permission to the app to access the storage. You have to put the permission tag in the AndroidMainfest.xml

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
   <application
       android:allowBackup="true"
       android:icon="@mipmap/ic_launcher"
       ...
   

Answer 3

but where to put the file examplelist.txt?

Your app would create the file itself. openFileInput() is part of internal storage, to which ordinary users have no access.

I would have used a simple 'File Selector', so the user can navigate to the file anywhere on the android phone, but this looks terribly complicated and cumbersome.

Step #1: Call startActivityForResult() with an ACTION_OPEN_DOCUMENT or ACTION_GET_CONTENT Intent (the former is for Android 4.4+)

Step #2: In onActivityResult(), if you get RESULT_OK as a result, get the Uri to the user's chosen content via getData() on the Intent passed into onActivityResult()

Step #3: Call openInputStream() on a ContentResolver to get an InputStream to use for reading the content

It's about 10-15 lines of code over what you have in your question, plus the code that your question needs but does not show (e.g., background thread for I/O).

Or, use a file chooser library.

I just want to open a file I can put somewhere on the phone in the most possible simple manner...

Use external storage, such as getExternalFilesDir().