I'm using Retrofit library from network calls. Pretty awesome. But I'm missing caching support. I can't using cache on HTTP layer (via Cache headers). Currently, I'm implementing custom caching with ObjectCache, but it's so complicated. It just should be awesome extend current Retrofit with #Cache(Expire.ONE_DAY) anotation.
My current code is like:
public static void getRestaurant(int restaurantId, String token, boolean forceNetwork, final Callback<Restaurant> listener) {
final String key = "getRestaurant-" + restaurantId + "-" + token;
Restaurant restaurant = (Restaurant) getCacheManager().get(key, Restaurant.class, new TypeToken<Restaurant>() {}.getType());
if (restaurant != null && !forceNetwork) {
Log.d(TAG, "Cache hit: " + key);
// Cache
listener.success(restaurant);
} else {
Log.d(TAG, "Network: " + key);
// Retrofit
getNetwork().getRestaurant(restaurantId, token, new retrofit.Callback<Response>() {
#Override
public void success(Response response, retrofit.client.Response response2) {
getCacheManager().put(key, response.result.restaurant, CacheManager.ExpiryTimes.ONE_HOUR.asSeconds(), true);
listener.success(response.result.restaurant);
}
#Override
public void failure(RetrofitError error) {
listener.failure(error.getLocalizedMessage());
}
});
}
}
Now, it's just a lot of boilerplate code for each method.
Or do you know any library like Retrofit with caching support?
Thanks!
You can wrap the underlying Client and use the request URL as a cache key.
public class CachingClient implements Client {
private final Client delegate;
#Override public Response execute(Request request) {
if (!"GET".equals(request.method())) {
return delegate.execute(request);
}
String url = request.url();
// TODO look up 'url' in your cache.
if (cacheHit) {
return createResponse(cacheResult);
}
// Cache miss! Execute with the real HTTP client.
Response response = delegate.execute(request);
// TODO cache 'response' in your cache with the 'url' key.
return response;
}
}
With Retrofit v2 we are looking to enable this kind of functionality with interceptors which will not only give you a hook into the request/response chain but also allow looking up a custom annotation like #Cache.
Related
I am developing simple Android app where I am using google spreadsheet as a data source. For communication I am using google app script which implements doPost method because my app is sending some data to sheet and also wants some data as a response. The problem is instead of json response I always get html response about redirection in the errorBody().
I have also set OkHttpClient with redirections enabled to my retrofit service, but result is still the same.
I am working with Insomnia rest client for debugging and when I set redirections on there, everything works there fine.
If somebody had the same problem and solved it, please help.
Edit:
Here is my code:
public class Connector {
private static final String BASE_URL = "https://script.googleusercontent.com/";
private static final Object LOCK = new Object();
private static CallTaxiService service;
private static final String TAG = "Connector";
private static CallTaxiService getService()
{
if (service == null)
{
synchronized(LOCK) {
Log.d(TAG, "creating instance");
service = buildService();
}
}
return service;
}
private static CallTaxiService buildService()
{
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.client(new OkHttpClient.Builder().followRedirects(true)
.followSslRedirects(true).build())
.addConverterFactory(GsonConverterFactory.create())
.build();
return retrofit.create(CallTaxiService.class);
}
public static void syncData(List<TaxiServiceAppData> data, Callback<Response> callback)
{
Call<Response> call = getService().sendData(data);
Log.d(TAG, "syncing data");
call.enqueue(callback);
}
private interface CallTaxiService {
#Headers({"Content-type: application/json"})
#POST("endpoint_url")
Call<Response> sendData(#Body List<TaxiServiceAppData> data);
}
}
And here is how I am calling it:
Connector.syncData(taxiServiceAppData, new retrofit2.Callback<com.adrisoft.calltaxi.model.Response>() {
#Override
public void onResponse(Call<com.adrisoft.calltaxi.model.Response> call, Response<com.adrisoft.calltaxi.model.Response> response) {
com.adrisoft.calltaxi.model.Response data = response.body();
if (data != null) {
newCities = data.getCities();
newTaxis = data.getTaxis();
updateDb();
prefs.saveSyncTime();
isSyncRunning = false;
callback.onSuccess();
} else {
try {
Log.d(TAG, "Sync failed ... no data available. Error: " + response.errorBody().string());
} catch (Exception ex) {
}
callback.onFailure();
}
}
#Override
public void onFailure(Call<com.adrisoft.calltaxi.model.Response> call, Throwable t) {
Log.d(TAG, "Sync request failed.");
isSyncRunning = false;
callback.onFailure();
}
});
And exactly in the log "Sync failed ... no data available ..." I am getting this from errorBody():
<HTML>
<HEAD>
<TITLE>Temporary Redirect</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Temporary Redirect</H1>
The document has moved here.
</BODY>
</HTML>
Redirect could have happened because the server endpoint provided https and in your code you call http. Then the server would redirect to https. Only GET requests can be redirected, so others like POST will result in error.
How I use these query in retrofit network call and display it in category wise result
https://api.themoviedb.org/3/genre/{genre_id}/movies
Perhaps this could help:
interface class
public interface TheApiInterface{
#GET("url/bits/until/{path_variable}/then/more/url")
Call<TheThingResponse> getTheThing(#Path("path_variable") String var);
}
Activity or whatever:
public class ThePlaceYoureCallingItFrom {
//set up the api interface and http client
public TheApiInterface getApi(){
String endpoint = "https://api.root.site/api/";
//set up retrofit object
return new Retrofit.Builder().baseUrl(endpoint)
//add chosen converter factory for pojo serialization
.addConverterFactory(GsonConverterFactory.create())
//add the OKHTTP client
.client(new OkHttpClient.Builder().build())
//now gimme
.build().create(TheApiInterface.class);
}
public void callGetTheThing(){
//create call
Call<TheThingResponse> call = getApi().getTheThing("somePathVar");
//set callback
ThingResponseCallback callback = new ThingResponseCallback(this, THING_RESPONSE_INTENT_FILTER);
//fire
call.enqueue(callback);
}
}
the callback:
public class ThingResponseCallback implements Callback<TheThingResponse>{
#Override
public void onResponse(Call<TheThingResponse> call, Response<TheThingResponse> response) {
if (response.isSuccessful() && response.body() != null) {
Log.i(TAG, "onResponse: success: theResponseFieldIWant1: " + response.theResponseFieldIWant1;);
} else {
Log.i(TAG, "onResponse: something went wrong with the response object " +response.body());
}
}
#Override
public void onFailure(Call<TheThingResponse> call, Throwable t) {
Log.i(TAG, "onFailure: to: " + call.request().url() + " req " + call.request());
}
}
the response pojo:
public class TheThingResponse{
#SerializedName("theJsonKeyOfTheFieldReturnedInServerResponse1")
public String theResponseFieldIWant1;
#SerializedName("theJsonKeyOfTheFieldReturnedInServerResponse2")
public String theResponseFieldIWant2;
#SerializedName("theJsonKeyOfTheFieldReturnedInServerResponse3")
public String theResponseFieldIWant3;
#SerializedName("theJsonKeyOfTheFieldReturnedInServerResponse4")
public String theResponseFieldIWant4;
}
the JSON you're receiving would look like this:
{
"theJsonKeyOfTheFieldReturnedInServerResponse1": "the value I wanted 1",
"theJsonKeyOfTheFieldReturnedInServerResponse2": "the value I wanted 2",
"theJsonKeyOfTheFieldReturnedInServerResponse3": "the value I wanted 3",
"theJsonKeyOfTheFieldReturnedInServerResponse4": "the value I wanted 4"
}
but you can build more complex POJOs for more complex JSON.
I've found it useful to make my POJOs all share a Serializable parent class, to make them easy to move about in the Callback, but you could also use a ContentProvider in here quite readily and insert some rows into a DB or something like that if you want to have a more permanent storage.
But bear in mind this is all async- if you want synchronous Retrofit calls, you can use call.execute()
At least in the "retrofit" library, it works like this
#GET("/url/{id}")
suspend fun getNews(
#Path("id") searchById:String
):Response<News>
I need a working example for a custom API for Microsoft Azure App Service.
I could not get any useful or working information/examples for that, or they just show each time different approaches which are outdated?!?!
For now I have a working table controller which gets information from database and returns it back to my Android client. Now I need to define a custom API Controller to get a string back. In the examples they are all sending an object to the service in order to get an object back. I do not want to send anything to the API, just retrieve some information back from a GET Request.
Regards
// EDIT - Added / edited client / server code to Post a String.
You can use the following code to do a GET request on the auto generated API controller Visual Studio creates (ValuesController).
private void getStringFromAzure() throws MalformedURLException {
// Create the MobileService Client object and set your backend URL
String yourURL = "https://yourApp.azurewebsites.net/";
MobileServiceClient mClient = new MobileServiceClient(yourURL, this);
// Your query pointing to yourURL/api/values
ListenableFuture<JsonElement> query = mClient.invokeApi("values", null, GetMethod, null);
// Callback method
Futures.addCallback(query, new FutureCallback<JsonElement>() {
#Override
public void onSuccess(JsonElement jsonElement) {
// You are expecting a String you can just output the result.
final String result = jsonElement.toString();
// Since you are on a async task, you need to show the result on the UI thread
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(mContext, result, Toast.LENGTH_LONG).show();
}
});
}
#Override
public void onFailure(Throwable throwable) {
Log.d(TAG, "onFailure: " + throwable.getMessage());
}
});
}
public void sendString(final String someString) throws MalformedURLException {
// Your query pointing to /api/values/{String}
ListenableFuture<JsonElement> query = mClient.invokeApi("values/" + someString, null, PostMethod, null);
// Callback method
Futures.addCallback(query, new FutureCallback<JsonElement>() {
#Override
public void onSuccess(JsonElement jsonElement) {
// You are expecting a String you can just output the result.
final String result = jsonElement.toString();
}
#Override
public void onFailure(Throwable throwable) { }
});
}
The backend API: (ValuesController)
{
// Use the MobileAppController attribute for each ApiController you want to use
// from your mobile clients
[MobileAppController]
public class ValuesController : ApiController
{
// GET api/values
public string Get()
{
return "Hello World!";
}
// POST api/values/inputString
public string Post(string inputString)
{
return inputString;
}
}
}
You can also send parameters along in the following way:
List<Pair<String, String>> parameters = new ArrayList<>();
parameters.add(new Pair<>("name", "John"));
parameters.add(new Pair<>("password", "fourwordsalluppercase"));
ListenableFuture<JsonElement> query = client.invokeApi("yourAPI", PostMethod, parameters);
Or as json in the body:
JsonObject body = new JsonObject();
body.addProperty("currentPassword", currentPassword);
body.addProperty("password", password);
body.addProperty("confirmPassword", confirmPassword);
ListenableFuture<JsonElement> query = mClient.invokeApi("yourAPI", body, PostMethod, null);
Based on my understanding, I think there are two parts in your question which include as below. And I think you can separately refer to two sections to get the answers and write your own example.
How to define a custom API on Azure Mobile App to retrieve data from database? Please refer to the section Custom APIs to know how to do with Azure Mobile App backend.
How to call a custom API from Android App? Please refer to the section How to: Call a custom API to know how to do with Android SDK.
I'm trying to use Retrofit (2.0.0-beta3), but when using an Authenticator to add a token, I can't seem to get the data from the synchronous call. Our logging on the back-end just shows a lot of login attempts, but I can't get the data from the body to actually add to the header.
public static class TokenAuthenticator implements Authenticator {
#Override
public Request authenticate(Route route, Response response) throws IOException {
// Refresh your access_token using a synchronous api request
UserService userService = createService(UserService.class);
Call<Session> call = userService.emailLogin(new Credentials("handle", "pass"));
// This call is made correctly, as it shows up on the back-end.
Session body = call.execute().body();
// This line is never hit.
Logger.d("Session token: " + body.token);
// Add new header to rejected request and retry it
return response.request().newBuilder()
.header("Auth-Token", body.token)
.build();
}
}
I'm not exactly too sure on why it's not even printing anything out. Any tips on how to solve this issue would be greatly appreciated, thanks for taking the time to help.
These are the sources I've been reading on how to implement Retrofit.
Using Authenticator:
https://stackoverflow.com/a/31624433/3106174
https://github.com/square/okhttp/wiki/Recipes#handling-authentication
Making synchronous calls with Retrofit 2:
https://futurestud.io/blog/retrofit-synchronous-and-asynchronous-requests
I managed to get a decent solution using the TokenAuthenticator and an Interceptor and thought I'd share the idea as it may help some others.
Adding the 'TokenInterceptor' class that handles adding the token to the header is the token exists, and the 'TokenAuthenticator' class handles the case when there is no token, and we need to generate one.
I'm sure there are some better ways to implement this, but it's a good starting point I think.
public static class TokenAuthenticator implements Authenticator {
#Override
public Request authenticate( Route route, Response response) throws IOException {
...
Session body = call.execute().body();
Logger.d("Session token: " + body.token);
// Storing the token somewhere.
session.token = body.token;
...
}
private static class TokenInterceptor implements Interceptor {
#Override
public Response intercept( Chain chain ) throws IOException {
Request originalRequest = chain.request();
// Nothing to add to intercepted request if:
// a) Authorization value is empty because user is not logged in yet
// b) There is already a header with updated Authorization value
if (authorizationTokenIsEmpty() || alreadyHasAuthorizationHeader(originalRequest)) {
return chain.proceed(originalRequest);
}
// Add authorization header with updated authorization value to intercepted request
Request authorisedRequest = originalRequest.newBuilder()
.header("Auth-Token", session.token )
.build();
return chain.proceed(authorisedRequest);
}
}
Source:
http://lgvalle.xyz/2015/07/27/okhttp-authentication/
I have similar authenticator and it works with 2.0.0-beta2.
If you get lots of login attempts from you Authenticator, I suggest make sure that when you make the synchronous call, you are not using Authenticator with that call.
That could end up in loop, if also your "emailLogin" fails.
Also I would recommend adding loggingInterceptor to see all trafic to server: Logging with Retrofit 2
I know it's a late answer but for anyone still wondering how to Add / Refresh token with Retrofit 2 Authenticator, here is a working solution:
Note: preferenceHelper is your Preference Manager class where you set/get your shared preferences.
public class AuthenticationHelper implements Authenticator {
private static final String HEADER_AUTHORIZATION = "Authorization";
private static final int REFRESH_TOKEN_FAIL = 403;
private Context context;
AuthenticationHelper(#ApplicationContext Context context) {
this.context = context;
}
#Override
public Request authenticate(#NonNull Route route, #NonNull Response response) throws IOException {
// We need to have a token in order to refresh it.
String token = preferencesHelper.getAccessToken();
if (token == null)
return null;
synchronized (this) {
String newToken = preferencesHelper.getAccessToken();
if (newToken == null)
return null;
// Check if the request made was previously made as an authenticated request.
if (response.request().header(HEADER_AUTHORIZATION) != null) {
// If the token has changed since the request was made, use the new token.
if (!newToken.equals(token)) {
return response.request()
.newBuilder()
.removeHeader(HEADER_AUTHORIZATION)
.addHeader(HEADER_AUTHORIZATION, "Bearer " + newToken)
.build();
}
JsonObject refreshObject = new JsonObject();
refreshObject.addProperty("refreshToken", preferencesHelper.getRefreshToken());
retrofit2.Response<UserToken> tokenResponse = apiService.refreshToken(refreshObject).execute();
if (tokenResponse.isSuccessful()) {
UserToken userToken = tokenResponse.body();
if (userToken == null)
return null;
preferencesHelper.saveAccessToken(userToken.getToken());
preferencesHelper.saveRefreshToken(userToken.getRefreshToken());
// Retry the request with the new token.
return response.request()
.newBuilder()
.removeHeader(HEADER_AUTHORIZATION)
.addHeader(HEADER_AUTHORIZATION, "Bearer " + userToken.getToken())
.build();
} else {
if (tokenResponse.code() == REFRESH_TOKEN_FAIL) {
logoutUser();
}
}
}
}
return null;
}
private void logoutUser() {
// logout user
}
}
Also note:
preferenceHelper and apiService needs to be provided in some way.
This is not an example that will work for all systems and api's but an example in how adding and refreshing the token should be done using Retrofit 2 Authenticator
I want to observer changes from server in my android app.
So I'm using this interface for open stream with server.
public interface Service {
#GET("/n/{id}/streaming")
void streamThreads(#Path("name_space_id") String Id, #QueryMap Map<String, String> options,#Query("exclude_types") String type, Callback<Object> callback);
}
and this is my method where I can get response in my activity
server.streamThreads(accountInfo.getId(), map, "thread", new Callback<Object>() {
#Override
public void success(Object o, Response response) {
String json = (String) o;
Log.i(TAG,json);
}
#Override
public void failure(RetrofitError error) {
Response r = error.getResponse();
if (r != null)
Log.e(TAG, "error: " + r.getReason());
}
});
So I tested method in web browser and life stream works.
But response comes in my mobile app every 30 minutes. I'm using one activity and call method onCreate().
Thanks
Retrofit provides an #Streaming annotation.
The unread byteStream can then be obtained from the raw OkHttp ResponseBody.