Unsupported operation: Android, Retrofit, OkHttp. Adding interceptor in OkHttpClient

Question

I am trying to add token based authentication via Retrofit 2.0-beta3 and OkHttpClient in Android using interceptors. But I get UnsupportedOperationException when I add my interceptor in OkHttpClient. Here is my code: In ApiClient.java

public static TrequantApiInterface getClient(final String token) {         if( sTreqantApiInterface == null) {              Log.v(RETROFIT_LOG, "Creating api client for the first time");             OkHttpClient okClient = new OkHttpClient();              okClient.interceptors().add(new Interceptor() {                 @Override                 public Response intercept(Interceptor.Chain chain) throws IOException {                     Request original = chain.request();                      // Request customization: add request headers                     Request.Builder requestBuilder = original.newBuilder()                             .header("Authorization", token)                             .method(original.method(), original.body());                      Request request = requestBuilder.build();                     return chain.proceed(request);                 }             });              Retrofit client = new Retrofit.Builder()                     .baseUrl(baseUrl)                     .client(okClient)                     .addConverterFactory(GsonConverterFactory.create())                     .build();             sTreqantApiInterface = client.create(TrequantApiInterface.class);         }         return sTreqantApiInterface;     } 

And I use it like:

private void ampFreqTest(){     String token = getSharedPreferences(getString(R.string.preference_file_key), Context.MODE_PRIVATE)                         .getString(getString(R.string.key_token), "");      service = ApiClient.getClient(token);     //I get an exception on this line:     Call<List<AmpFreq>> call = service.getUserAmpFreq("1");     call.enqueue(new Callback<List<AmpFreq>>() {         @Override         public void onResponse(Response<List<AmpFreq>> response) {             Toast.makeText(HomeScreen.this, "Got result", Toast.LENGTH_LONG);              Log.v(ApiClient.RETROFIT_LOG, "Success api client." + response.message());             Log.v(ApiClient.RETROFIT_LOG, "Success api client.");         }         @Override         public void onFailure(Throwable t) {             Toast.makeText(HomeScreen.this, t.getMessage() , Toast.LENGTH_LONG);             Log.v(ApiClient.RETROFIT_LOG, "Fail api client." + t.getMessage() );         }     }); } 

But I get this error:

Process: com.trequant.usman.trequant_android, PID: 14400 java.lang.UnsupportedOperationException at java.util.Collections$UnmodifiableCollection.add(Collections.java:932)  at com.trequant.usman.trequant_android.api.ApiClient.getClient(ApiClient.java:41) 

It gives me error on adding a new interceptor saying that it is not modifiableCollection but the documentation for interceptors() function says: /**

   * Returns a modifiable list of interceptors that observe the full span of each call: from before    * the connection is established (if any) until after the response source is selected (either the    * origin server, cache, or both).    */ 

What am I doing wrong? Could it be a bug?

Answer 1

This issue occurs when you change Retrofit 2.0-beta2 to Retrofit 2.0-beta3. You have to use builder if you want to create OkHttpClient object.

Change :

 OkHttpClient okClient = new OkHttpClient();   okClient.interceptors().add(new Interceptor() {        @Override        public Response intercept(Interceptor.Chain chain) throws IOException {             Request original = chain.request();              // Request customization: add request headers             Request.Builder requestBuilder = original.newBuilder()                     .header("Authorization", token)                     .method(original.method(), original.body());              Request request = requestBuilder.build();             return chain.proceed(request);         }  }); 

to :

 OkHttpClient okClient = new OkHttpClient.Builder()            .addInterceptor(                new Interceptor() {                  @Override                  public Response intercept(Interceptor.Chain chain) throws IOException {                        Request original = chain.request();                         // Request customization: add request headers                        Request.Builder requestBuilder = original.newBuilder()                                .header("Authorization", token)                                .method(original.method(), original.body());                         Request request = requestBuilder.build();                        return chain.proceed(request);                    }                })            .build(); 

It should resolve your problem.