Develop Reference

Retrofit getMessage in onFailure returns null

I use these libraries in my app:
implementation 'com.squareup.retrofit2:retrofit:2.4.0'
implementation 'com.squareup.retrofit2:converter-gson:2.3.0'
implementation 'com.squareup.okhttp3:okhttp:3.10.0'
It is my RetrofitClientInstance class implementations:
public class RetrofitClientInstance {
private static Retrofit retrofit;
private static final String BASE_URL = "my basic url";
public static Retrofit getRetrofitInstance() {
OkHttpClient okHttpClient = new OkHttpClient().newBuilder()
.connectTimeout(30, TimeUnit.SECONDS)
.readTimeout(30, TimeUnit.SECONDS)
.writeTimeout(30, TimeUnit.SECONDS)
.build();
if (retrofit == null) {
retrofit = new retrofit2.Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(okHttpClient)
.build();
}
return retrofit;
}
}
Until this morning it was no problem but from this morning it is not working and getMessage in onFailure returns null and t.toString() returns java.net.SocketTimeoutException. (It is Ok on postman still).
#Override
public void onFailure(#NonNull Call<List<Ad>> call, #NonNull Throwable t) {
call.clone().enqueue(this);
Log.e("error in SplashScreen", "!!" + t.getMessage());
}
What is the problem?

From the javadoc for retrofit
onFailure(Call<T> call, Throwable t)
Invoked when a network exception occurred talking to the server or when an unexpected exception occurred creating the request or processing the response.
If your specific request is okay on POSTMAN, then there is no chance that it could be going on the onFailure() callback unless:
The android client is not connected to the Internet.
The Base URL or the endpoint is wrong.
You are calling for a resource ie. List<Ad>that the endpoint cannot return.
Your Request type (POST/GET/PUT/..) is wrong.
The response is not available within the default timeout declared in the api client. code: new OkHttpClient.Builder().connectTimeout(100, TimeUnit.SECONDS) //connect timeout
In addition to that I only do the following in my onFailure() callback and it works like a charm:
Log.e(TAG, t.getLocalizedMessage());
Log.e(TAG, t.getMessage());
t.printStackTrace();

How to send post request with basic auth in retrofit?

In my code, I want to send post request with basic auth.
Here is my postman screenshot :
here is my apiInterface class
#FormUrlEncoded
#POST("GetBarcodeDetail")
Call<PreliminaryGoodsAcceptResponse> PRELIMINARY_GOODS_ACCEPT_RESPONSE_CALL(#Field("ProcName") String procName, #Field("Barcode") String barcode, #Field("LangCode") String langCode);
here is my apiclient
public class ApiClient {
public static final String BASE_URL = "http://192.**********";
private static Retrofit retrofit = null;
private static OkHttpClient sClient;
public static Retrofit getClient() {
if(sClient == null) {
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
sClient = new OkHttpClient.Builder()
.addInterceptor(new HttpLoggingInterceptor(HttpLoggingInterceptor.Logger.DEFAULT))
.addInterceptor(interceptor)
.build();
}
if (retrofit==null) {
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(sClient)
.build();
}
return retrofit;
}
}
My question is how can i send post request,using header :
Header Username : EBA Token :
34242353453456563DSFS

This is so far the easiest method i have ever tried for "Basic Authentication".
Use the below code to generate the auth header (API/Repository class)
var basic = Credentials.basic("YOUR_USERNAME", "YOUR_PASSWORD")
Pass this as header to the webservice call (API/Repository class)
var retrofitCall = myWebservice.getNewsFeed(basic)
Add the basic header as parameter (Retrofit Webservice interface class)
#GET("newsfeed/daily")
fun getNewsFeed(#Header("Authorization") h1:String):Call<NewsFeedResponse>
Sorry, my code is in Kotlin, but can be easily translated to Java.
References: https://mobikul.com/basic-authentication-retrofit-android/

make header like this way..
private Retrofit getClient(final Context context) {
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient.Builder client = new OkHttpClient.Builder();
client.readTimeout(60, TimeUnit.SECONDS);
client.writeTimeout(60, TimeUnit.SECONDS);
client.connectTimeout(60, TimeUnit.SECONDS);
client.addInterceptor(interceptor);
client.addInterceptor(new Interceptor() {
#Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
if (context == null) {
request = request
.newBuilder()
.build();
} else {
request = request
.newBuilder()
.addHeader("Authorization", "Bearer " + AppSetting.getStringSharedPref(context, Constants.USER_KEY_TOKEN, ""))
.build();
}
return chain.proceed(request);
}
});
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.client(client.build())
.addConverterFactory(GsonConverterFactory.create())
.build();
return retrofit;
}

Use Header annotation
#FormUrlEncoded
#POST("GetBarcodeDetail")
Call<PreliminaryGoodsAcceptResponse> PRELIMINARY_GOODS_ACCEPT_RESPONSE_CALL(#Header("Authorization") token: String,#Field("ProcName") String procName, #Field("Barcode") String barcode, #Field("LangCode") String langCode);

Simple-Retrofit-API-request-and-Data-Loading Here I just add the project where create the API call to access data from database using retrofit library; which is leading library to access data on network. And display the accessed data in the List format. Create the Simple Android Studio Project with Empty Activity. Create the Adapter and activity item to show normal lists in android app. Now Create the App class extending Application, as Application class is a singleton that you can access from any activity or anywhere else you have a Context object.
You can check the more details about Application class from https://github.com/codepath/android_guides/wiki/Understanding-the-Android-Application-Class Why extend an Application class? https://developer.android.com/reference/android/app/Application.html
Add android:name=".YourApplication" i.e. class name extending the Application class in android. and class will be like public class YourApplication extends Application Init the Retrofit in Application class
//network code start
//init http logger
httpLoggingInterceptor = new HttpLoggingInterceptor();
httpLoggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
// init client client = new OkHttpClient.Builder()
.addInterceptor(httpLoggingInterceptor)
.addInterceptor(new Interceptor() {
#Override public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
Request request2 = request.newBuilder().build();
return chain.proceed(request2);
}
}).connectTimeout(30, TimeUnit.SECONDS).writeTimeout(30, TimeUnit.SECONDS).readTimeout(30, TimeUnit.SECONDS).build();
Gson gson = new GsonBuilder().setLenient().create();
Retrofit mRetrofit = new Retrofit.Builder().baseUrl(Constants.API_BASE_URL).client(client).addConverterFactory(GsonConverterFactory.create(gson)).build();
mWebservice = mRetrofit.create(Webservice.class);
While Constants.API_BASE_URL is base url Create the Webervice.class where you can call the API with parameters e.g. In case of GET Method:
#GET("webservices/GetAllClientsDemoRetro.php")
Call updateChatStatus();
In case of POST method:
#FormUrlEncoded
#Headers({"Content-Type: application/x-www-form-urlencoded"})
#POST("webservices/GetAllClientsDemoRetro.php")
Call updateChatStatus();
You can See the more in details About Retrofit on Official API declaration here: http://square.github.io/retrofit/
We can parse the values with POJO i.e. Setter and Getter, using the Parceble class. Since parsing key name should be equal to the value we are receiving from the JSON response. POJO class should be declared like public class ClientData implements Parcelable { then declare the keys in the class, key values means
public class ClientData implements Parcelable
{
public String client_id;
public String company_name;
public String address_line;
public String city;
public String pincode;
public String state;
public String country;
}
Now using Alt+Enter i.e. select the option Add Parceble Implementation and press enter. Then automatically parceble class will be added. Also you have to add Setter and Getter method in class using Alt + Insert. Note: Don’t add the Setter and Getter methods for CREATER: Creater<> method If you want to use different key that JSON response key, then you should use Serialization. When I was using same key then its is like public String client_id; But when I am using the Serialization, then I can use like #Serializattion(“client_id”) public String ClientID; Now last but not a list, We call the API using retrofit, and use the response to view the Item in list-
RetroFitApplication.getWebservice().updateChatStatus().enqueue(new Callback() {
#Override public void onResponse(Call call, Response response) {
Log.d("retrofilt success", "" + response.body());
if (response.body() != null) {
clientResponceData = response.body();
Gson gson = new Gson();
String body = gson.toJson(response.body());
Log.d("retrofilt success2", "clientData" + clientResponceData.getResponse());
if (clientResponceData.getResponse() != null) {
initRV();
}
} else {
// Empty Client List Toast.makeText(ClientList.this, "Empty List", Toast.LENGTH_SHORT).show();
}
}
#Override public void onFailure(Call call, Throwable t) {
Log.d("retrofilt error", "" + t);
Toast.makeText(ClientList.this, "No Internet Connection", Toast.LENGTH_SHORT).show();
}
});
By using the Construction in Adapter, we can use the values from the response. Guys I added this repository to get the Entire idea of calling the API and get the response from server using the Retrofit Library. I write this entire documents in details with simple word.

How to handle No Network connection using Retrofit 2.0 in Android?

I am using Retrofit 2.0 library in my android application by adding it into build.gradle file
// retrofit, gson
compile 'com.google.code.gson:gson:2.6.2'
compile 'com.squareup.retrofit2:retrofit:2.0.2'
compile 'com.squareup.retrofit2:converter-gson:2.0.2'
related code is given below
ApiInterface.java
public interface ApiInterface {
#GET("contacts/")
Call<ContactsModel> getContactsList();
}
ApiClient.java
public class ApiClient {
public static final String BASE_URL = "http://myexamplebaseurl/";
private static Retrofit retrofit = null;
public static Retrofit getClient() {
if (retrofit == null) {
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
}
MainActivity.java
ApiInterface apiService = ApiClient.getClient().create(ApiInterface.class);
Call<ContactsModel> call = apiService.getContactsList();
call.enqueue(new Callback<ContactsModel>() {
#Override
public void onResponse(Call<ContactsModel> call, Response<ContactsModel> response) {
if(response.isSuccessful()){
/*here is my data handling*/
}
}
#Override
public void onFailure(Call<ContactsModel> call, Throwable t) {
/*It is the request failure case,
I want to differentiate Request timeout, no internet connection and any other reason behind the request failure
*/
}
});
if we get status code as 4xx or 5xx even though onResponse() will called, so there we need handle that condition also.
Here my question is, How to differentiate reason for request failure i.e onFailure() by using Retrofit 2.0 in Android?

Here my question is, How to differentiate reason for request failure
by using Retrofit 2.0 in Android?
if you have a 4xx or 5xx error, onResponse is still called. There you have to check the response code of the code to check if everything was fine. E.g
if (response.code() < 400) {
in case of No Network connection, onFailure is called. There you could check the instance of the throwable. Typically an IOException

Set dynamic base url using Retrofit 2.0 and Dagger 2

I'm trying to perform a login action using Retrofit 2.0 using Dagger 2
Here's how I set up Retrofit dependency
#Provides
#Singleton
Retrofit provideRetrofit(Gson gson, OkHttpClient client) {
Retrofit retrofit = new Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create(gson)
.client(client)
.baseUrl(application.getUrl())
.build();
return retrofit;
}
Here's the API interface.
interface LoginAPI {
#GET(relative_path)
Call<Boolean> logMe();
}
I have three different base urls users can log into. So I can't set a static url while setting up Retrofit dependency. I created a setUrl() and getUrl() methods on Application class. Upon user login, I set the url onto Application before invoking the API call.
I use lazy injection for retrofit like this
Lazy<Retrofit> retrofit
That way, Dagger injects dependency only when I can call
retrofit.get()
This part works well. I got the url set to retrofit dependency. However, the problem arises when the user types in a wrong base url (say, mywifi.domain.com), understands it's the wrong one and changes it(say to mydata.domain.com). Since Dagger already created the dependency for retrofit, it won't do again.
So I have to reopen the app and type in the correct url.
I read different posts for setting up dynamic urls on Retrofit using Dagger. Nothing really worked out well in my case. Do I miss anything?

Support for this use-case was removed in Retrofit2. The recommendation is to use an OkHttp interceptor instead.
HostSelectionInterceptor made by swankjesse
import java.io.IOException;
import okhttp3.HttpUrl;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
/** An interceptor that allows runtime changes to the URL hostname. */
public final class HostSelectionInterceptor implements Interceptor {
private volatile String host;
public void setHost(String host) {
this.host = host;
}
#Override public okhttp3.Response intercept(Chain chain) throws IOException {
Request request = chain.request();
String host = this.host;
if (host != null) {
//HttpUrl newUrl = request.url().newBuilder()
// .host(host)
// .build();
HttpUrl newUrl = HttpUrl.parse(host);
request = request.newBuilder()
.url(newUrl)
.build();
}
return chain.proceed(request);
}
public static void main(String[] args) throws Exception {
HostSelectionInterceptor interceptor = new HostSelectionInterceptor();
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.addInterceptor(interceptor)
.build();
Request request = new Request.Builder()
.url("http://www.coca-cola.com/robots.txt")
.build();
okhttp3.Call call1 = okHttpClient.newCall(request);
okhttp3.Response response1 = call1.execute();
System.out.println("RESPONSE FROM: " + response1.request().url());
System.out.println(response1.body().string());
interceptor.setHost("www.pepsi.com");
okhttp3.Call call2 = okHttpClient.newCall(request);
okhttp3.Response response2 = call2.execute();
System.out.println("RESPONSE FROM: " + response2.request().url());
System.out.println(response2.body().string());
}
}
Or you can either replace your Retrofit instance (and possibly store the instance in a RetrofitHolder in which you can modify the instance itself, and provide the holder through Dagger)...
public class RetrofitHolder {
Retrofit retrofit;
//getter, setter
}
Or re-use your current Retrofit instance and hack the new URL in with reflection, because screw the rules. Retrofit has a baseUrl parameter which is private final, therefore you can access it only with reflection.
Field field = Retrofit.class.getDeclaredField("baseUrl");
field.setAccessible(true);
okhttp3.HttpUrl newHttpUrl = HttpUrl.parse(newUrl);
field.set(retrofit, newHttpUrl);

Retrofit2 library comes with a #Url annotation. You can override baseUrl like this:
API interface:
public interface UserService {
#GET
public Call<ResponseBody> profilePicture(#Url String url);
}
And call the API like this:
Retrofit retrofit = Retrofit.Builder()
.baseUrl("https://your.api.url/");
.build();
UserService service = retrofit.create(UserService.class);
service.profilePicture("https://s3.amazon.com/profile-picture/path");
For more details refer to this link: https://futurestud.io/tutorials/retrofit-2-how-to-use-dynamic-urls-for-requests

This worked for me in Kotlin
class HostSelectionInterceptor: Interceptor {
override fun intercept(chain: Interceptor.Chain): Response {
var request = chain.request()
val host: String = SharedPreferencesManager.getServeIpAddress()
val newUrl = request.url().newBuilder()
.host(host)
.build()
request = request.newBuilder()
.url(newUrl)
.build()
return chain.proceed(request)
}
}
Add the interceptor to OkHttpClient builder
val okHttpClient = OkHttpClient.Builder()
.addInterceptor(HostSelectionInterceptor())
.cache(null)
.build()

This might be late but Retrofit allows you to use dynamic URLs while making the network call itself using #Url annotation.
I am also using Dagger2 to inject the Retrofit instance in my repositories and this solution is working fine for me.
This will use the base url
provided by you while creating the instance of Retrofit.
#GET("/product/123")
fun fetchDataFromNetwork(): Call<Product>
This ignore the base url
and use the url you will be providing this call at run time.
#GET()
fun fetchDataFromNetwork(#Url url : String): Call<Product> //

Thanks to #EpicPandaForce for help. If someone is facing IllegalArgumentException, this is my working code.
public class HostSelectionInterceptor implements Interceptor {
private volatile String host;
public void setHost(String host) {
this.host = HttpUrl.parse(host).host();
}
#Override
public okhttp3.Response intercept(Chain chain) throws IOException {
Request request = chain.request();
String reqUrl = request.url().host();
String host = this.host;
if (host != null) {
HttpUrl newUrl = request.url().newBuilder()
.host(host)
.build();
request = request.newBuilder()
.url(newUrl)
.build();
}
return chain.proceed(request);
}
}

For latest Retrofit library, you can simply use singleton instance and change it with retrofitInstance.newBuilder().baseUrl(newUrl). No need to create another instance.

Dynamic url using Retrofit 2 and Dagger 2
You are able to instantiate new object using un-scoped provide method.
#Provides
LoginAPI provideAPI(Gson gson, OkHttpClient client, BaseUrlHolder baseUrlHolder) {
Retrofit retrofit = new Retrofit.Builder().addConverterFactory(GsonConverterFactory.create(gson)
.client(client)
.baseUrl(baseUrlHolder.get())
.build();
return retrofit.create(LoginAPI.class);
}
#AppScope
#Provides
BaseUrlHolder provideBaseUrlHolder() {
return new BaseUrlHolder("https://www.default.com")
}
public class BaseUrlHolder {
public String baseUrl;
public BaseUrlHolder(String baseUrl) {
this.baseUrl = baseUrl;
}
public String getBaseUrl() {
return baseUrl;
}
public void setBaseUrl(String baseUrl) {
this.baseUrl = baseUrl;
}
}
Now you can change base url via getting baseUrlHolder from the component
App.appComponent.getBaseUrlHolder().set("https://www.changed.com");
this.loginApi = App.appComponent.getLoginApi();

Please look into my workaround for Dagger dynamic URL.
Step1: Create an Interceptor
import android.util.Patterns;
import com.nfs.ascent.mdaas.repo.network.ApiConfig;
import java.io.IOException;
import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.Response;
public class DomainURLInterceptor implements Interceptor {
#Override
public Response intercept(Chain chain) throws IOException {
Request original = chain.request();
String requestUrl = original.url().toString();
String PROTOCOL = "(?i:http|https|rtsp)://";
String newURL = requestUrl.replaceFirst(PROTOCOL, "")
.replaceFirst(Patterns.DOMAIN_NAME.toString(), "");
newURL = validateBackSlash(newURL) ? ApiConfig.BASE_URL.concat(newURL) : newURL.replaceFirst("/", ApiConfig.BASE_URL);
original = original.newBuilder()
.url(newURL)
.build();
return chain.proceed(original);
}
private boolean validateBackSlash(String str) {
if (!str.substring(str.length() - 1).equals("/")) {
return true;
}
return false;
}
}
Step 2:
add your newly created interceptor in your module
#Provides
#Singlton
DomainURLInterceptor getChangeURLInterceptor() {
return new DomainURLInterceptor();
}
step 3:
add interceptor into list of HttpClient interceptors
#Provides
#Singlton
OkHttpClient provideHttpClient() {
return new OkHttpClient.Builder()
.addInterceptor(getChangeURLInterceptor())
.readTimeout(ApiConfig.API_CONNECTION_TIMEOUT, TimeUnit.SECONDS)
.connectTimeout(ApiConfig.API_CONNECTION_TIMEOUT, TimeUnit.SECONDS)
.build();
}
step 4:
#Provides
#Singlton
Retrofit provideRetrofit() {
return new Retrofit.Builder()
.baseUrl(ApiConfig.BASE_URL) // this is default URl,
.addConverterFactory(provideConverterFactory())
.client(provideHttpClient())
.build();
}
Note: if the user has to change the Base URL from settings, remember to validate the newly created URL with below method:
public final static boolean isValidUrl(CharSequence target) {
if (target == null) {
return false;
} else {
return Patterns.WEB_URL.matcher(target).matches();
}
}

Refreshing OAuth token using Retrofit without modifying all calls

We are using Retrofit in our Android app, to communicate with an OAuth2 secured server. Everything works great, we use the RequestInterceptor to include the access token with each call.
However there will be times, when the access token will expire, and the token needs to be refreshed. When the token expires, the next call will return with an Unauthorized HTTP code, so that's easy to monitor.
We could modify each Retrofit call the following way:
In the failure callback, check for the error code, if it equals Unauthorized, refresh the OAuth token, then repeat the Retrofit call.
However, for this, all calls should be modified, which is not an easily maintainable, and good solution.
Is there a way to do this without modifying all Retrofit calls?

Please do not use Interceptors to deal with authentication.
Currently, the best approach to handle authentication is to use the new Authenticator API, designed specifically for this purpose.
OkHttp will automatically ask the Authenticator for credentials when a response is 401 Not Authorised retrying last failed request with them.
public class TokenAuthenticator implements Authenticator {
#Override
public Request authenticate(Proxy proxy, Response response) throws IOException {
// Refresh your access_token using a synchronous api request
newAccessToken = service.refreshToken();
// Add new header to rejected request and retry it
return response.request().newBuilder()
.header(AUTHORIZATION, newAccessToken)
.build();
}
#Override
public Request authenticateProxy(Proxy proxy, Response response) throws IOException {
// Null indicates no attempt to authenticate.
return null;
}
Attach an Authenticator to an OkHttpClient the same way you do with Interceptors
OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.setAuthenticator(authAuthenticator);
Use this client when creating your Retrofit RestAdapter
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint(ENDPOINT)
.setClient(new OkClient(okHttpClient))
.build();
return restAdapter.create(API.class);

If you are using Retrofit >= 1.9.0 then you could make use of OkHttp's new Interceptor, which was introduced in OkHttp 2.2.0. You would want to use an Application Interceptor, which permits you to retry and make multiple calls.
Your Interceptor could look something like this pseudocode:
public class CustomInterceptor implements Interceptor {
#Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
// try the request
Response response = chain.proceed(request);
if (response shows expired token) {
// close previous response
response.close()
// get a new token (I use a synchronous Retrofit call)
// create a new request and modify it accordingly using the new token
Request newRequest = request.newBuilder()...build();
// retry the request
return chain.proceed(newRequest);
}
// otherwise just pass the original response on
return response;
}
}
After you define your Interceptor, create an OkHttpClient and add the interceptor as an Application Interceptor.
OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.interceptors().add(new CustomInterceptor());
And finally, use this OkHttpClient when creating your RestAdapter.
RestService restService = new RestAdapter().Builder
...
.setClient(new OkClient(okHttpClient))
.create(RestService.class);
Warning: As Jesse Wilson (from Square) mentions here, this is a dangerous amount of power.
With that being said, I definitely think this is the best way to handle something like this now. If you have any questions please don't hesitate to ask in a comment.

TokenAuthenticator depends an a service class. The service class depends on an OkHttpClient instance. To create an OkHttpClient I need the TokenAuthenticator. How can I break this cycle? Two different OkHttpClients? They are going to have different connection pools..
If you have, say, a Retrofit TokenService that you need inside your Authenticator but you would only like to set up one OkHttpClient you can use a TokenServiceHolder as a dependency for TokenAuthenticator. You would have to maintain a reference to it at the application (singleton) level. This is easy if you are using Dagger 2, otherwise just create class field inside your Application.
In TokenAuthenticator.java
public class TokenAuthenticator implements Authenticator {
private final TokenServiceHolder tokenServiceHolder;
public TokenAuthenticator(TokenServiceHolder tokenServiceHolder) {
this.tokenServiceHolder = tokenServiceHolder;
}
#Override
public Request authenticate(Proxy proxy, Response response) throws IOException {
//is there a TokenService?
TokenService service = tokenServiceHolder.get();
if (service == null) {
//there is no way to answer the challenge
//so return null according to Retrofit's convention
return null;
}
// Refresh your access_token using a synchronous api request
newAccessToken = service.refreshToken().execute();
// Add new header to rejected request and retry it
return response.request().newBuilder()
.header(AUTHORIZATION, newAccessToken)
.build();
}
#Override
public Request authenticateProxy(Proxy proxy, Response response) throws IOException {
// Null indicates no attempt to authenticate.
return null;
}
In TokenServiceHolder.java:
public class TokenServiceHolder {
TokenService tokenService = null;
#Nullable
public TokenService get() {
return tokenService;
}
public void set(TokenService tokenService) {
this.tokenService = tokenService;
}
}
Client setup:
//obtain instance of TokenServiceHolder from application or singleton-scoped component, then
TokenAuthenticator authenticator = new TokenAuthenticator(tokenServiceHolder);
OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.setAuthenticator(tokenAuthenticator);
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.github.com/")
.client(okHttpClient)
.build();
TokenService tokenService = retrofit.create(TokenService.class);
tokenServiceHolder.set(tokenService);
If you are using Dagger 2 or a similar dependency injection framework there are some examples in the answers to this question

Using TokenAuthenticator like #theblang answer is a correct way for handle refresh_token.
Here is my implement (I have using Kotlin, Dagger, RX but you may use this idea for implement to your case)
TokenAuthenticator
class TokenAuthenticator #Inject constructor(private val noneAuthAPI: PotoNoneAuthApi, private val accessTokenWrapper: AccessTokenWrapper) : Authenticator {
override fun authenticate(route: Route, response: Response): Request? {
val newAccessToken = noneAuthAPI.refreshToken(accessTokenWrapper.getAccessToken()!!.refreshToken).blockingGet()
accessTokenWrapper.saveAccessToken(newAccessToken) // save new access_token for next called
return response.request().newBuilder()
.header("Authorization", newAccessToken.token) // just only need to override "Authorization" header, don't need to override all header since this new request is create base on old request
.build()
}
}
For prevent dependency cycle like #Brais Gabin comment, I create 2 interface like
interface PotoNoneAuthApi { // NONE authentication API
#POST("/login")
fun login(#Body request: LoginRequest): Single<AccessToken>
#POST("refresh_token")
#FormUrlEncoded
fun refreshToken(#Field("refresh_token") refreshToken: String): Single<AccessToken>
}
and
interface PotoAuthApi { // Authentication API
#GET("api/images")
fun getImage(): Single<GetImageResponse>
}
AccessTokenWrapper class
class AccessTokenWrapper constructor(private val sharedPrefApi: SharedPrefApi) {
private var accessToken: AccessToken? = null
// get accessToken from cache or from SharePreference
fun getAccessToken(): AccessToken? {
if (accessToken == null) {
accessToken = sharedPrefApi.getObject(SharedPrefApi.ACCESS_TOKEN, AccessToken::class.java)
}
return accessToken
}
// save accessToken to SharePreference
fun saveAccessToken(accessToken: AccessToken) {
this.accessToken = accessToken
sharedPrefApi.putObject(SharedPrefApi.ACCESS_TOKEN, accessToken)
}
}
AccessToken class
data class AccessToken(
#Expose
var token: String,
#Expose
var refreshToken: String)
My Interceptor
class AuthInterceptor #Inject constructor(private val accessTokenWrapper: AccessTokenWrapper): Interceptor {
override fun intercept(chain: Interceptor.Chain): Response {
val originalRequest = chain.request()
val authorisedRequestBuilder = originalRequest.newBuilder()
.addHeader("Authorization", accessTokenWrapper.getAccessToken()!!.token)
.header("Accept", "application/json")
return chain.proceed(authorisedRequestBuilder.build())
}
}
Finally, add Interceptor and Authenticator to your OKHttpClient when create service PotoAuthApi
Demo
https://github.com/PhanVanLinh/AndroidMVPKotlin
Note
Authenticator flow
Example API getImage() return 401 error code
authenticate method inside TokenAuthenticator will fired
Synchronize noneAuthAPI.refreshToken(...) called
After noneAuthAPI.refreshToken(...) response -> new token will add to header
getImage() will AUTO called with new header (HttpLogging WILL NOT log this call) (intercept inside AuthInterceptor WILL NOT CALLED)
If getImage() still failed with error 401, authenticate method inside TokenAuthenticator will fired AGAIN and AGAIN then it will throw error about call method many time(java.net.ProtocolException: Too many follow-up requests). You can prevent it by count response. Example, if you return null in authenticate after 3 times retry, getImage() will finish and return response 401
If getImage() response success => we will result the result normally (like you call getImage() with no error)
Hope it help

As Brais Gabin said in the comment I had the problem that TokenAuthenticator depends on a service class. The service class depends on an OkHttpClient instance and to create an OkHttpClient I need the TokenAuthenticator.
So how I broke this cycle?
I created a new okHttpClient object, a new Retrofit object and with that object I did the call to get the new token using the refreshToken ( check getUpdatedToken() function)
class TokenAuthenticator : Authenticator {
override fun authenticate(route: Route?, response: Response): Request? {
return runBlocking {
// 1. Refresh your access_token using a synchronous api request
val response = getUpdatedToken(refreshToken)
//2. In my case here I store the new token and refreshToken into SharedPreferences
response.request.newBuilder()
.header("Authorization", "Bearer ${tokenResponse.data?.accessToken}")
.build()
// 3. If there's any kind of error I return null
}
}
private suspend fun getUpdatedToken( refreshToken: String): TokenResponse {
val okHttpClient = OkHttpClient().newBuilder()
.addInterceptor(errorResponseInterceptor)
.build()
val retrofit = Retrofit.Builder()
.baseUrl(BuildConfig.BASE_URL)
.client(okHttpClient)
.addConverterFactory(MoshiConverterFactory.create())
.build()
val service = retrofit.create(RefreshTokenApi::class.java)
return service.refreshToken(refreshToken)
}
}
RefreshTokenApi
interface RefreshTokenApi {
#FormUrlEncoded
#POST("refreshToken")
suspend fun refreshToken(
#Field("refresh_token") refreshToeken: String
): TokenResponse
}
In this project I'm using Koin and I configured this way:
object RetrofigConfig {
fun provideRetrofit(okHttpClient: OkHttpClient): Retrofit {
return Retrofit.Builder()
.baseUrl(BuildConfig.BASE_URL)
.client(okHttpClient)
.addConverterFactory(MoshiConverterFactory.create())
.build()
}
fun provideOkHttpClient(
tokenAuthenticator: TokenAuthenticator
): OkHttpClient {
return OkHttpClient().newBuilder()
.authenticator(tokenAuthenticator)
.build()
}
fun provideServiceApi(retrofit: Retrofit): ServiceApi {
return retrofit.create(ServiceApi::class.java)
}
}
The important line there is OkHttpClient().newBuilder().authenticator(tokenAuthenticator)
Because this is the first time I'm implementing this I don't know if this is the best way but is the way it is working in my project.

I know this an old thread, but just in case someone stumbled in it.
TokenAuthenticator depends an a service class. The service class depends on an OkHttpClient instance. To create an OkHttpClient I need the TokenAuthenticator. How can I break this cycle? Two different OkHttpClients? They are going to have different connection pools..
I was facing the same problem, but I wanted to create only one OkHttpClient becuase I don't think that I need another one for just the TokenAuthenticator itself, I was using Dagger2, so I ended up providing the service class as Lazy injected in the TokenAuthenticator, you can read more about Lazy injection in dagger 2 here, but it's like basically saying to Dagger to NOT go and create the service needed by the TokenAuthenticator right away.
You can refer to this SO thread for sample code: How to resolve a circular dependency while still using Dagger2?

Using one Interceptor (inject the token) and one Authenticator (refresh operations) do the job but:
I had a double call problem too: the first call always returned a 401:
the token wasn't inject at the first call (interceptor) and the authenticator was called: two requests were made.
The fix was just to reaffect the request to the build in the Interceptor:
BEFORE:
private Interceptor getInterceptor() {
return (chain) -> {
Request request = chain.request();
//...
request.newBuilder()
.header(AUTHORIZATION, token))
.build();
return chain.proceed(request);
};
}
AFTER:
private Interceptor getInterceptor() {
return (chain) -> {
Request request = chain.request();
//...
request = request.newBuilder()
.header(AUTHORIZATION, token))
.build();
return chain.proceed(request);
};
}
IN ONE BLOCK:
private Interceptor getInterceptor() {
return (chain) -> {
Request request = chain.request().newBuilder()
.header(AUTHORIZATION, token))
.build();
return chain.proceed(request);
};
}
Hope it helps.
Edit: I didn't find a way to avoid the first call to always returning 401 using only the authenticator and no interceptor

You can try creating a base class for all your loaders in which you would be able to catch a particular exception and then act as you need.
Make all your different loaders extend from the base class in order to spread the behaviour.

After Long research, I customized Apache client to handle Refreshing AccessToken For Retrofit In which you send access token as parameter.
Initiate your Adapter with cookie Persistent Client
restAdapter = new RestAdapter.Builder()
.setEndpoint(SERVER_END_POINT)
.setClient(new CookiePersistingClient())
.setLogLevel(RestAdapter.LogLevel.FULL).build();
Cookie Persistent client which maintains cookies for all requests and checks with each request response, if it is unauthorized access ERROR_CODE = 401, refresh access token and recall the request, else just processes request.
private static class CookiePersistingClient extends ApacheClient {
private static final int HTTPS_PORT = 443;
private static final int SOCKET_TIMEOUT = 300000;
private static final int CONNECTION_TIMEOUT = 300000;
public CookiePersistingClient() {
super(createDefaultClient());
}
private static HttpClient createDefaultClient() {
// Registering https clients.
SSLSocketFactory sf = null;
try {
KeyStore trustStore = KeyStore.getInstance(KeyStore
.getDefaultType());
trustStore.load(null, null);
sf = new MySSLSocketFactory(trustStore);
sf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
} catch (KeyManagementException e) {
e.printStackTrace();
} catch (UnrecoverableKeyException e) {
e.printStackTrace();
} catch (KeyStoreException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (CertificateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
HttpParams params = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(params,
CONNECTION_TIMEOUT);
HttpConnectionParams.setSoTimeout(params, SOCKET_TIMEOUT);
SchemeRegistry registry = new SchemeRegistry();
registry.register(new Scheme("https", sf, HTTPS_PORT));
// More customization (https / timeouts etc) can go here...
ClientConnectionManager cm = new ThreadSafeClientConnManager(
params, registry);
DefaultHttpClient client = new DefaultHttpClient(cm, params);
// Set the default cookie store
client.setCookieStore(COOKIE_STORE);
return client;
}
#Override
protected HttpResponse execute(final HttpClient client,
final HttpUriRequest request) throws IOException {
// Set the http context's cookie storage
BasicHttpContext mHttpContext = new BasicHttpContext();
mHttpContext.setAttribute(ClientContext.COOKIE_STORE, COOKIE_STORE);
return client.execute(request, mHttpContext);
}
#Override
public Response execute(final Request request) throws IOException {
Response response = super.execute(request);
if (response.getStatus() == 401) {
// Retrofit Callback to handle AccessToken
Callback<AccessTockenResponse> accessTokenCallback = new Callback<AccessTockenResponse>() {
#SuppressWarnings("deprecation")
#Override
public void success(
AccessTockenResponse loginEntityResponse,
Response response) {
try {
String accessToken = loginEntityResponse
.getAccessToken();
TypedOutput body = request.getBody();
ByteArrayOutputStream byte1 = new ByteArrayOutputStream();
body.writeTo(byte1);
String s = byte1.toString();
FormUrlEncodedTypedOutput output = new FormUrlEncodedTypedOutput();
String[] pairs = s.split("&");
for (String pair : pairs) {
int idx = pair.indexOf("=");
if (URLDecoder.decode(pair.substring(0, idx))
.equals("access_token")) {
output.addField("access_token",
accessToken);
} else {
output.addField(URLDecoder.decode(
pair.substring(0, idx), "UTF-8"),
URLDecoder.decode(
pair.substring(idx + 1),
"UTF-8"));
}
}
execute(new Request(request.getMethod(),
request.getUrl(), request.getHeaders(),
output));
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void failure(RetrofitError error) {
// Handle Error while refreshing access_token
}
};
// Call Your retrofit method to refresh ACCESS_TOKEN
refreshAccessToken(GRANT_REFRESH,CLIENT_ID, CLIENT_SECRET_KEY,accessToken, accessTokenCallback);
}
return response;
}
}

here is my code working for me. may be helpful for some one
class AuthenticationInterceptorRefreshToken #Inject
constructor( var hIltModules: HIltModules,) : Interceptor {
#Throws(IOException::class)
override fun intercept(chain: Interceptor.Chain): Response {
val originalRequest = chain.request()
val response = chain.proceed(originalRequest)
if (response.code == 401) {
synchronized(this) {
val originalRequest = chain.request()
val authenticationRequest = originalRequest.newBuilder()
.addHeader("refreshtoken", " $refreshToken")
.build()
val initialResponse = chain.proceed(authenticationRequest)
when (initialResponse.code) {
401 -> {
val responseNewTokenLoginModel = runBlocking {
hIltModules.provideAPIService().refreshToken()
}
when (responseNewTokenLoginModel.statusCode) {
200 -> {
refreshToken = responseNewTokenLoginModel.refreshToken
access_token = responseNewTokenLoginModel.accessToken
val newAuthenticationRequest = originalRequest.newBuilder()
.header("refreshtoken",
" $refreshToken")
.build()
return chain.proceed(newAuthenticationRequest)
}
else -> {
return null!!
}
}
}
else -> return initialResponse
}
}
}; return response
}

To anyone who wanted to solve concurrent/parallel calls when refreshing token. Here's a workaround
class TokenAuthenticator: Authenticator {
override fun authenticate(route: Route?, response: Response?): Request? {
response?.let {
if (response.code() == 401) {
while (true) {
if (!isRefreshing) {
val requestToken = response.request().header(AuthorisationInterceptor.AUTHORISATION)
val currentToken = OkHttpUtil.headerBuilder(UserService.instance.token)
currentToken?.let {
if (requestToken != currentToken) {
return generateRequest(response, currentToken)
}
}
val token = refreshToken()
token?.let {
return generateRequest(response, token)
}
}
}
}
}
return null
}
private fun generateRequest(response: Response, token: String): Request? {
return response.request().newBuilder()
.header(AuthorisationInterceptor.USER_AGENT, OkHttpUtil.UA)
.header(AuthorisationInterceptor.AUTHORISATION, token)
.build()
}
private fun refreshToken(): String? {
synchronized(TokenAuthenticator::class.java) {
UserService.instance.token?.let {
isRefreshing = true
val call = ApiHelper.refreshToken()
val token = call.execute().body()
UserService.instance.setToken(token, false)
isRefreshing = false
return OkHttpUtil.headerBuilder(token)
}
}
return null
}
companion object {
var isRefreshing = false
}
}