Retrofit2 Authorization - Global Interceptor for access token

You have two choices -- you can add it as a parameter to your call --

@GET("api/Profiles/GetProfile?id={id}")Call<UserProfile> getUser(@Path("id") String id, @Header("Authorization") String authHeader);

This can be a bit annoying because you will have to pass in the "Bearer" + token on each call. This is suitable if you don't have very many calls that require the token.

If you want to add the header to all requests, you can use an okhttp interceptor --

OkHttpClient client = new OkHttpClient.Builder().addInterceptor(new Interceptor() {      @Override      public Response intercept(Chain chain) throws IOException {        Request newRequest  = chain.request().newBuilder()            .addHeader("Authorization", "Bearer " + token)            .build();        return chain.proceed(newRequest);      }    }).build();Retrofit retrofit = new Retrofit.Builder()    .client(client)    .baseUrl(/** your url **/)    .addConverterFactory(GsonConverterFactory.create())    .build();

If you want to add Bearer Token as a Header you can do those types of process.

This is one way to work with Bearer Token

In your Interface

@Headers({ "Content-Type: application/json;charset=UTF-8"})@GET("api/Profiles/GetProfile")Call<UserProfile> getUser(@Query("id") String id, @Header("Authorization") String auth);

After that you will call the Retrofit object in this way

Retrofit retrofit  = new Retrofit.Builder()                    .baseUrl("your Base URL")                    .addConverterFactory(GsonConverterFactory.create())                    .build();APIService client = retrofit.create(APIService.class);Call<UserProfile> calltargetResponse = client.getUser("0034", "Bearer "+token);calltargetResponse.enqueue(new Callback<UserProfile>() {       @Override       public void onResponse(Call<UserProfile> call, retrofit2.Response<UserProfile> response) {           UserProfile UserResponse = response.body();           Toast.makeText(this, " "+response.body(), Toast.LENGTH_SHORT).show();                }        @Override        public void onFailure(Call<UserProfile> call, Throwable t) {            //Toast.makeText(this, "Failed ", Toast.LENGTH_SHORT).show();        }});

Another Way is using intercept, which is similar the previous Answer. But, that time you just need to modify interface little bit like.

@Headers({ "Content-Type: application/json;charset=UTF-8"})@GET("api/Profiles/GetProfile")Call<UserProfile> getUser(@Query("id") String id); 

Hope this will work for you.

Based on @iagreen solution kotlin version with different classes and structure suggested by @Daniel Wilson

Make Retrofit instance like this

object RetrofitClientInstance {   private var retrofit: Retrofit? = null   private val BASE_URL = "http://yoururl"    val retrofitInstance: Retrofit?        get() {            if (retrofit == null) {                var client = OkHttpClient.Builder()                      .addInterceptor(ServiceInterceptor())                      //.readTimeout(45,TimeUnit.SECONDS)                      //.writeTimeout(45,TimeUnit.SECONDS)                        .build()                retrofit = Retrofit.Builder()                        .baseUrl(BASE_URL)                        .client(client)                        .addConverterFactory(GsonConverterFactory.create())                        .build()            }            return retrofit      }}

Add ServiceInterceptor class like below

class ServiceInterceptor : Interceptor{  var token : String = "";  fun Token(token: String ) {     this.token = token;  }  override fun intercept(chain: Interceptor.Chain): Response {    var request = chain.request()    if(request.header("No-Authentication")==null){        //val token = getTokenFromSharedPreference();        //or use Token Function        if(!token.isNullOrEmpty())        {            val finalToken =  "Bearer "+token            request = request.newBuilder()                    .addHeader("Authorization",finalToken)                    .build()        }    }    return chain.proceed(request)  }}

Login Interface and data class implementation

interface Login {  @POST("Login")  @Headers("No-Authentication: true")  fun login(@Body value: LoginModel): Call<LoginResponseModel>  @POST("refreshToken")  fun refreshToken(refreshToken: String):       Call<APIResponse<LoginResponseModel>>}data class LoginModel(val Email:String,val Password:String)data class LoginResponseModel (val token:String,val          refreshToken:String)

call this in any activity like this

val service = RetrofitClientInstance.retrofitInstance?.create(Login::class.java)val refreshToken = "yourRefreshToken"val call = service?.refreshToken(refreshToken)        call?.enqueue(object: Callback<LoginResponseModel>{            override fun onFailure(call: Call<LoginResponseModel>, t: Throwable) {                print("throw Message"+t.message)                Toast.makeText(applicationContext,"Error reading JSON",Toast.LENGTH_LONG).show()            }            override fun onResponse(call: Call<LoginResponseModel>, response: Response<LoginResponseModel>) {                val body = response?.body()                if(body!=null){                    //do your work                }            }        })

for detail this video will be helpful.