Using JSON File in Android App Resources

Found this Kotlin snippet answer very helpful ♥️

While the original question asked to get a JSON String, I figure some might find this useful. A step further with Gson leads to this little function with reified type:

private inline fun <reified T> readRawJson(@RawRes rawResId: Int): T {
    resources.openRawResource(rawResId).bufferedReader().use {
        return gson.fromJson<T>(it, object: TypeToken<T>() {}.type)
    }
}

Note you want to use TypeToken not just T::class so if you read a List<YourType> you won't lose the type by type erasure.

With the type inference you can then use like this:

fun pricingData(): List<PricingData> = readRawJson(R.raw.mock_pricing_data)

Using:

String json_string = readRawResource(R.raw.json)

Functions:

public String readRawResource(@RawRes int res) {
    return readStream(context.getResources().openRawResource(res));
}

private String readStream(InputStream is) {
    Scanner s = new Scanner(is).useDelimiter("\\A");
    return s.hasNext() ? s.next() : "";
}