android write external file

Permission : writeExternalStorage

public  boolean isStoragePermissionGranted() {
    if (Build.VERSION.SDK_INT >= 23) {
        if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)
                == PackageManager.PERMISSION_GRANTED&&
                checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)
                        == PackageManager.PERMISSION_GRANTED) {
            Log.v(TAG,"Permission is granted");
            return true;
        } else {

            Log.v(TAG,"Permission is revoked");
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
            return false;
        }
    }
    else { //permission is automatically granted on sdk<23 upon installation        Log.v(TAG,"Permission is granted");
        return true;
    }
}

private void writeFileToSD() {

    String sdStatus = Environment.getExternalStorageState();    

if(!sdStatus.equals(Environment.MEDIA_MOUNTED)) {
        Log.d("TestFile", "SD card is not avaiable/writeable right now.");        

return;    

}
    try {
        String pathName="/sdcard/test/";        String fileName="file.txt";        File path = new File(pathName);        File file = new File(pathName + fileName);        if( !path.exists()) {
            Log.d("TestFile", "Create the path:" + pathName);            path.mkdir();        }
        if( !file.exists()) {
            Log.d("TestFile", "Create the file:" + fileName);            file.createNewFile();        }
        FileOutputStream stream = new FileOutputStream(file);        String s = "this is a test string writing to file.";        byte[] buf = s.getBytes();        stream.write(buf);        stream.close();
    } catch(Exception e) {
        Log.e("TestFile", "Error on writeFilToSD.");        e.printStackTrace();    }
}