Place your text file in the /assets directory under the Android project and use AssetManager class as follows to access it.
AssetManager am = context.getAssets();
InputStream is = am.open("default_book.txt");
Or you can also put the file in the /res/raw directory, from where the file can be accessed by an id as follows
InputStream is =
context.getResources().openRawResource(R.raw.default_book);