[android] Retrofit 2 - Dynamic URL

With Retrofit 2, you can set a full URL in the annotation of a service method like :

public interface APIService {
  @GET("http://api.mysite.com/user/list")
  Call<Users> getUsers();
}

However, in my app, the URL of my webservices are not known at compile time, the app retrieves them in a downloaded file so i'm wondering how i can use Retrofit 2 with full dynamic URL.

I tried to set a full path like :

public interface APIService {
  @GET("{fullUrl}")
  Call<Users> getUsers(@Path("fullUrl") fullUrl);
}

new Retrofit.Builder()
  .baseUrl("http://api.mysite.com/")
  .build()
  .create(APIService.class)
  .getUsers("http://api.mysite.com/user/list"); // this url should be dynamic
  .execute();

But here, Retrofit doesn't see that the path is actually a full URL and is trying to download http://api.mysite.com/http%3A%2F%2Fapi.mysite.com%2Fuser%2Flist

Any hint of how I could use Retrofit with such dynamic url ?

Thank you

This question is related to android retrofit

The answer is


You can use this :

@GET("group/{id}/users")

Call<List<User>> groupList(@Path("id") int groupId, @Query("sort") String sort);

For more information see documentation https://square.github.io/retrofit/


Dynamic URL with Get and Post method in Retrofit (MVVM)

Retrofit Service interface:

public interface NetworkAPIServices {

@POST()
Observable<JsonElement> executXYZServiceAPI(@Url String url,@Body AuthTokenRequestModel param);


@GET
Observable<JsonElement> executeInserInfo(@Url String url);

MVVM service class:

   public Observable<JsonElement> executXYZServiceAPI(ModelObject object) {
    return networkAPIServices.authenticateAPI("url",
            object);
}

 public Observable<JsonElement> executeInserInfo(String ID) {
    return networkAPIServices.getBank(DynamicAPIPath.mergeUrlPath("url"+ID)));
}

and Retrofit Client class

 @Provides
@Singleton
@Inject
@Named("provideRetrofit2")
Retrofit provideRetrofit(@Named("provideRetrofit2") Gson gson, @Named("provideRetrofit2") OkHttpClient okHttpClient) {


   builder = new Retrofit.Builder();
    if (BaseApplication.getInstance().getApplicationMode() == ApplicationMode.DEVELOPMENT) {
        builder.baseUrl(NetworkURLs.BASE_URL_UAT);
    } else {
        builder.baseUrl(NetworkURLs.BASE_URL_PRODUCTION);
    }


    builder.addCallAdapterFactory(RxJava2CallAdapterFactory.create());
    builder.client(okHttpClient);
    builder.addConverterFactory(GsonConverterFactory.create(gson));


    return builder.build();
}

for example This is url : https://gethelp.wildapricot.com/en/articles/549-changing-your

baseURL : https://gethelp.wildapricot.com

Remaining @Url: /en/articles/549-changing-your (which is you pass in retro service class)


As of Retrofit 2.0.0-beta2, if you have a service responding JSON from this URL : http://myhost/mypath

The following is not working :

public interface ClientService {
    @GET("")
    Call<List<Client>> getClientList();
}

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("http://myhost/mypath")
    .addConverterFactory(GsonConverterFactory.create())
    .build();

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

Response<List<Client>> response = service.getClientList().execute();

But this is ok :

public interface ClientService {
    @GET
    Call<List<Client>> getClientList(@Url String anEmptyString);
}

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("http://myhost/mypath")
    .addConverterFactory(GsonConverterFactory.create())
    .build();

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

Response<List<Client>> response = service.getClientList("").execute();

step -*1 

movie_list_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?android:attr/selectableItemBackground"
    android:clickable="true"
    android:focusable="true"

    android:orientation="horizontal"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/row_padding_vertical"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingBottom="@dimen/row_padding_vertical">

    <ImageView
        android:id="@+id/ivImage"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_marginRight="10dp"
        android:src="@mipmap/ic_launcher" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:orientation="vertical">

        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:text="Hello"
            android:textColor="@color/title"
            android:textSize="16dp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/genre"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/title"
            android:text="realName" />
    </LinearLayout>

    <TextView
        android:id="@+id/year"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:text="Team"
        android:textColor="@color/year" />

</LinearLayout>                                                                                                            

Api.java                                                                                  
import org.json.JSONObject;

import java.util.List;

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.http.Field;
import retrofit2.http.FormUrlEncoded;
import retrofit2.http.GET;
import retrofit2.http.POST;

public interface  Api {

    String BASE_URL = "https://simplifiedcoding.net/demos/";

    @GET("marvel")
    Call<List<Hero>> getHeroes();

    @FormUrlEncoded
    @POST("/login")
    public void login(@Field("username") String username, @Field("password") String password, Callback<List<Hero>> callback);

}


MoviesAdapter.java                                                                                       import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.squareup.picasso.Picasso;

import java.util.List;

public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MyViewHolder> {

    private List<Hero> moviesList;

    Context context;


    public class MyViewHolder extends RecyclerView.ViewHolder {
        public TextView title, year, genre;
        public ImageView ivImage;

        public MyViewHolder(View view) {
            super(view);
            title = (TextView) view.findViewById(R.id.title);
            genre = (TextView) view.findViewById(R.id.genre);
            year = (TextView) view.findViewById(R.id.year);
            ivImage =  view.findViewById(R.id.ivImage);
            ivImage.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    Toast.makeText(context, "-" + moviesList.get(getAdapterPosition()).getName(), Toast.LENGTH_SHORT).show();
                }
            });
        }
    }


    public MoviesAdapter(List<Hero> moviesList,Context context) {
        this.moviesList = moviesList;
        this.context = context;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.movie_list_row, parent, false);

        return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        Hero movie = moviesList.get(position);
        holder.title.setText(movie.getName());
        holder.genre.setText(movie.getRealname());
        holder.year.setText(movie.getTeam());

        Picasso.get().load("http://i.imgur.com/DvpvklR.png").into(holder.ivImage);
    }

    @Override
    public int getItemCount() {
        return moviesList.size();
    }
}                                                                                                                                                        main activity                                                                                                               import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public class MainActivity extends AppCompatActivity {

    private List<Hero> movieList = new ArrayList<>();
    private RecyclerView recyclerView;
    private MoviesAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView=findViewById(R.id.recycler_view);
        mAdapter = new MoviesAdapter(movieList,MainActivity.this);
        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);
        //calling the method to display the heroes
        getHeroes();

    }


    private void getHeroes() {
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(ApiInterface.BASE_URL)
                .addConverterFactory(GsonConverterFactory.create()) //Here we are using the GsonConverterFactory to directly convert json data to object
                .build();

        ApiInterface api = retrofit.create(ApiInterface.class);

        Call<List<Hero>> call = api.getHeroes();

        call.enqueue(new Callback<List<Hero>>() {
            @Override
            public void onResponse(Call<List<Hero>> call, Response<List<Hero>> response) {
                List<Hero> heroList = response.body();

                //Creating an String array for the ListView
                String[] heroes = new String[heroList.size()];

                //looping through all the heroes and inserting the names inside the string array
                for (int i = 0; i < heroList.size(); i++) {
                    //heroes[i] = heroList.get(i).getName();
                    movieList.add(new Hero( heroList.get(i).getName(), heroList.get(i).getRealname(), heroList.get(i).getTeam()));
                }
                mAdapter.notifyDataSetChanged();

            }

            @Override
            public void onFailure(Call<List<Hero>> call, Throwable t) {
                Toast.makeText(getApplicationContext(), t.getMessage(), Toast.LENGTH_SHORT).show();
            }
        });
    }

}
Hero.java
package com.example.owner.apipractice;
public class Hero {

    private String name;
    private String realname;
    private String team;

    public Hero(String name, String realname, String team) {
        this.name = name;
        this.realname = realname;
        this.team = team;
    }

    private String firstappearance;
    private String createdby;
    private String publisher;
    private String imageurl;
    private String bio;


    public Hero(String name, String realname, String team, String firstappearance, String createdby, String publisher, String imageurl, String bio) {
        this.name = name;
        this.realname = realname;
        this.team = team;
        this.firstappearance = firstappearance;
        this.createdby = createdby;
        this.publisher = publisher;
        this.imageurl = imageurl;
        this.bio = bio;
    }

    public String getName() {
        return name;
    }

    public String getRealname() {
        return realname;
    }

    public String getTeam() {
        return team;
    }

    public String getFirstappearance() {
        return firstappearance;
    }

    public String getCreatedby() {
        return createdby;
    }

    public String getPublisher() {
        return publisher;
    }

    public String getImageurl() {
        return imageurl;
    }

    public String getBio() {
        return bio;
    }
}

Step-1

  Please define a method in Api interface like:-
 @FormUrlEncoded
 @POST()
 Call<RootLoginModel> getForgotPassword(
        @Url String apiname,
        @Field(ParameterConstants.email_id) String username
 );

Step-2 For a best practice define a class for retrofit instance:-

  public class ApiRequest {
       static Retrofit retrofit = null;



public static Retrofit getClient() {
    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);

    OkHttpClient okHttpClient = new OkHttpClient().newBuilder()
            .addInterceptor(logging)
            .connectTimeout(60, TimeUnit.SECONDS)
            .readTimeout(60, TimeUnit.SECONDS)
            .writeTimeout(60, TimeUnit.SECONDS)
            .build();

    if (retrofit==null) {
        retrofit = new Retrofit.Builder()
                .baseUrl(URLConstants.base_url)
                .client(okHttpClient)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
    }
    return retrofit;
}

} Step-3 define in your activity:-

  final APIService request =ApiRequest.getClient().create(APIService.class);
  Call<RootLoginModel> call = request.getForgotPassword("dynamic api 
  name",strEmailid);

I wanted to replace only a part of the url, and with this solution, I don't have to pass the whole url, just the dynamic part:

public interface APIService {

  @GET("users/{user_id}/playlists")
  Call<List<Playlist> getUserPlaylists(@Path(value = "user_id", encoded = true) String userId);
}

If you already have your code setup and you don’t want to make changes on the different interfaces you can, use the solution described in this link. The main point is the method changeApiBaseUrl that updates the URL and recreates the Retrofit builder.

public class ServiceGenerator {  
public static String apiBaseUrl = "http://futurestud.io/api";
private static Retrofit retrofit;

private static Retrofit.Builder builder =
        new Retrofit.Builder()
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl(apiBaseUrl);

private static OkHttpClient.Builder httpClient =
        new OkHttpClient.Builder();

// No need to instantiate this class.
private ServiceGenerator() {
}

public static void changeApiBaseUrl(String newApiBaseUrl) {
    apiBaseUrl = newApiBaseUrl;

    builder = new Retrofit.Builder()
                    .addConverterFactory(GsonConverterFactory.create())
                    .baseUrl(apiBaseUrl);
}

public static <S> S createService(Class<S> serviceClass, AccessToken token) {
    String authToken = token.getTokenType().concat(token.getAccessToken());
    return createService(serviceClass, authToken);
}

// more methods
// ...
}

You can use it as follows:

public class DynamicBaseUrlActivity extends AppCompatActivity {

public static final String TAG = "CallInstances";
private Callback<ResponseBody> downloadCallback;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_file_upload);

    downloadCallback = new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            Log.d(TAG, "server contacted at: " + call.request().url());
        }

        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            Log.d(TAG, "call failed against the url: " + call.request().url());
        }
    };

    // first request
    FileDownloadService downloadService = ServiceGenerator.create(FileDownloadService.class);
    Call<ResponseBody> originalCall = downloadService.downloadFileWithFixedUrl();
    originalCall.enqueue(downloadCallback);

    // change base url
    ServiceGenerator.changeApiBaseUrl("http://development.futurestud.io/api");

    // new request against new base url
    FileDownloadService newDownloadService = ServiceGenerator.create(FileDownloadService.class);
    Call<ResponseBody> newCall = newDownloadService.downloadFileWithFixedUrl();
    newCall.enqueue(downloadCallback);
    }
}

You can use the encoded flag on the @Path annotation:

public interface APIService {
  @GET("{fullUrl}")
  Call<Users> getUsers(@Path(value = "fullUrl", encoded = true) String fullUrl);
}
  • This will prevent the replacement of / with %2F.
  • It will not save you from ? being replaced by %3F, however, so you still can't pass in dynamic query strings.

RetrofitHelper library written in kotlin, will let you make API calls, using a few lines of code and you can use different URLs, Headers and Params, in every Call.

Add multiple URLs in your application class like this :

class Application : Application() {

    override fun onCreate() {
    super.onCreate()

        retrofitClient = RetrofitClient.instance
                    //api url
                .setBaseUrl("https://reqres.in/")
                    //you can set multiple urls
        //                .setUrl("example","http://ngrok.io/api/")
                    //set timeouts
                .setConnectionTimeout(4)
                .setReadingTimeout(15)
                    //enable cache
                .enableCaching(this)
                    //add Headers
                .addHeader("Content-Type", "application/json")
                .addHeader("client", "android")
                .addHeader("language", Locale.getDefault().language)
                .addHeader("os", android.os.Build.VERSION.RELEASE)
            }

        companion object {
        lateinit var retrofitClient: RetrofitClient

        }
    }  

And then use the URL you need in your call:

retrofitClient.Get<GetResponseModel>()
            //set base url
            .setBaseUrlKey("example")
            //set path
            .setPath("api/users/2")
            //set url params Key-Value or HashMap
            .setUrlParams("KEY","Value")
            .setResponseHandler(GetResponseModel::class.java,
                object : ResponseHandler<GetResponseModel>() {
                    override fun onSuccess(response: Response<GetResponseModel>) {
                        super.onSuccess(response)
                        //handle response
                    }
                }).run(this)

For more information see the documentation