I'm using a android-priority-jobqueue and I use retrofit to make synchronous calls to my rest api but i'm unsure how to handle errors like 401 Unauthorized errors which I send back json stating the error. Simple when doing async calls but I'm adapting my app for job manager. below is a simple try catch for IO exceptions, but 401's 422's etc? How to do this?
try {
PostService postService = ServiceGenerator.createService(PostService.class);
final Call<Post> call = postService.addPost(post);
Post newPost = call.execute().body();
// omitted code here
} catch (IOException e) {
// handle error
}
EDIT
The use of the retrofit response object was the clincher for me, returning the retrofit response object allowed me to
Response<Post> response = call.execute();
if (response.isSuccessful()) {
// request successful (status code 200, 201)
Post result = response.body();
// publish the post added event
EventBus.getDefault().post(new PostAddedEvent(result));
} else {
// request not successful (like 400,401,403 etc and 5xx)
renderApiError(response);
}
Check response code and show the appropriate message.
Try this:
PostService postService = ServiceGenerator.createService(PostService.class);
final Call<Post> call = postService.addPost(post);
Response<Post> newPostResponse = call.execute();
// Here call newPostResponse.code() to get response code
int statusCode = newPostResponse.code();
if(statusCode == 200)
Post newPost = newPostResponse.body();
else if(statusCode == 401)
// Do some thing...
Putting checks for 401 on every response is not a very good approach. Instead one can apply this check at the base level i.e. while creating an object for Retrofit, through the interceptors. Have a look:
public synchronized static Retrofit getClientWithRetry(final Context ctx) {
if (clientWithRetry == null) {
Interceptor responseCodeInterceptor = new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
Response response = chain.proceed(request);
if (response.code() == 401) {
Log.d(LOG_TAG, "Intercepted Req: " + response.toString());
Response r = retryWithFreshToken(request, chain);
return r;
}
return response;
}
};
int cacheSize = 10 * 1024 * 1024; // 10 MB
Cache cache = new Cache(ctx.getCacheDir(), cacheSize);
HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client = new OkHttpClient.Builder()
.addInterceptor(logging)
.addInterceptor(responseCodeInterceptor)
.cache(cache)
.build();
Retrofit.Builder builder = new Retrofit.Builder()
.baseUrl(API_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(client);
clientWithRetry = builder.build();
}
return clientWithRetry;
}
Here internally if a 401 is observed a new chained request can be made and token can be fetched. Post which the original request can be completed. Taken from this Retrofit retry tutorial.
