Failed to find configured root that contains /data/data/com.example.bluetoothdemo/

Question

I'm trying to send a simple text file via Bluetooth using Android's default functionality. I've been trying to wrap my head around using Content Provider and Uri but keep encountering this error.

java.lang.IllegalArgumentException: Failed to find configured root that contains /data/data/com.example.bluetoothdemo/app_MyFiles/bluetooth.txt

This is my AndroidManifext.xml file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.bluetoothdemo">
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <application
       ...
        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="${applicationId}.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths" />
        </provider>
    ...
    </application>
</manifest>

My Activity file

public class MyBluetoothActivity extends Activity {
    public void clickToTransfer(View view) {
        File directory = new File(this.getExternalFilesDir("") + "/MyFiles");
        if (!directory.exists()) {
            directory.mkdirs();
        }
        File dir = getApplicationContext().getDir("MyFiles", MODE_PRIVATE);

        File file = new File(dir, "bluetooth.txt");
        if (!file.exists()) {
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        FileOutputStream fos = null;
        OutputStreamWriter osw = null;
        try {
            fos = new FileOutputStream(file, true);
            osw = new OutputStreamWriter(fos);
            osw.write("abc \n");
            osw.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                osw.close();
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.setType("text/plain");
        intent.setComponent(new ComponentName("com.android.bluetooth", "com.android.bluetooth.opp.BluetoothOppLauncherActivity"));
        Uri uri = FileProvider.getUriForFile(MyBluetoothActivity.this, this.getApplicationContext().getPackageName() + ".provider", file);
        intent.putExtra(Intent.EXTRA_STREAM, uri);
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
        startActivity(intent);
    }
}

Also, my target sdk is sdk25. Can someone help me?

Edit: My provider_paths.xml file

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-files-path name="external_files" path="."/>
</paths>

Answer 1

Ok, as suggested, I was being dumb and used getDir() which cannot be used for FileProvider.

I switched back to using getExternalFilesDir() with the <external_file_paths> instead of just <external_paths> in the xml file and everything works now.