Dynamic Link crawl using Retrofit2

Question

I am implementing Link preview feature like WhatsApp, i.e

1. Provided any link, fetch all its Html
2. Crawl through Html, read all information
3. Display text and images

Jsoup Library

I am successfully able to perform this using Jsoup library

Document doc = Jsoup.connect("http://www.techjuice.pk").userAgent("Mozilla").get();

It returns the html code of the page as a response.

---

Retrofit Library

Now I wanted to perform the same task using Retrofit

Retrofit retrofit = new Retrofit.Builder()
                    .build();
API api = retrofit.create(API.class);
Call<ResponseBody> call = api.crawlLink("http://techjuice.pk");
call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
    }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
    }
});

API.class

public interface API {

    @GET
    Call<ResponseBody> crawlLink(@Url String url);

}

Exception

java.lang.IllegalStateException: Base URL required.

Answer 1

Unfortunatelly you can't change URL in Retrofit at Runtime in that way.

Try this tutorial: https://futurestud.io/tutorials/retrofit-2-how-to-change-api-base-url-at-runtime-2

or this answer: Set dynamic base url using Retrofit 2.0 and Dagger 2