Retrofit 2 removes characters after hostname from base url

Ashkan Sarlak picture Ashkan Sarlak · Sep 2, 2015 · Viewed 23.6k times · Source

I'm using Retrofit to access a RESTful api. The base url is:

http://api.example.com/service

This is the code for the interface:

public interface ExampleService {
    @Headers("Accept: Application/JSON")
    @POST("/album/featured-albums")
    Call<List<Album>> listFeaturedAlbums();
}

and this is how I send request and receive the responce:

new AsyncTask<Void, Void, Response<List<Album>>>() {

        @Override
        protected Response<List<Album>> doInBackground(Void... params) {
            Retrofit retrofit = new Retrofit.Builder()
                    .baseUrl("http://api.example.com/service")
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();

            ExampleService service = retrofit.create(ExampleService.class);

            try {
                return service.listFeaturedAlbums().execute();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Response<List<Album>> listCall) {
            Log.v("Example", listCall.raw().toString());
        }
    }.execute();

the log that I get is the weird thing:

V/Example﹕ Response{protocol=http/1.1, code=404, message=Not Found, url=http://api.example.com/album/featured-albums}

What's going on here?

Answer

Jake Wharton picture Jake Wharton · Sep 2, 2015

Retrofit 2 uses the same rules that an <a href=""> would.

The leading / on your relative URL tells Retrofit that it is an absolute path on the host. Here's an example from a presentation I gave showing this:

enter image description here

Note the incorrect URL which was resolved at the bottom.

By removing the leading /, the URL then becomes relative and will combine with the path segments which are part of the base URL. Corrected in the presentation the final URL is now correct:

enter image description here

In your example you do not have a trailing / on the base URL. You probably want to add one so that relative paths are resolved on top of it rather than as a sibling of it.