I'm trying to learn how Retrofit+RxJava work and I'm testing some example. If I call a List of objects I can print on console this list of objects. Here below the code:
Disposable disposable = apiInterface.getArea("4744", ".")
.observeOn(AndroidSchedulers.mainThread())
.subscribeOn(Schedulers.io())
.subscribeWith(new DisposableObserver<List<Area>>() {
#Override
public void onNext(List<Area> areas) {
Log.d("Response"," Value Area "+areas);
}
#Override
public void onError(Throwable e) {
Log.d("Error","JSON Error "+ e.getMessage());
}
#Override
public void onComplete() {
}
}
);
Model class:
public class Area {
#SerializedName("v_area")
private String typeArea;
#SerializedName("area")
private String desArea;
public Area(String typeArea, String desArea) {
this.typeArea = typeArea;
this.desArea = desArea;
}
public String getTypeArea() {
return typeArea;
}
public void setTypeArea(String typeArea) {
this.typeArea = typeArea;
}
public String getDesArea() {
return desArea;
}
public void setDesArea(String desArea) {
this.desArea = desArea;
}
}
Whereas if I try to receive a list of objects and convert in a list of strings with RxJava operators I get the error:"D/OkHttp: <-- HTTP FAILED: android.os.NetworkOnMainThreadException"
Disposable disposable = apiInterface.getArea("4744",".")
.map(response -> Observable.fromIterable(response))
.flatMap(x->x)
.map(Area::getTypeArea)
.toList()
.toObservable()
.subscribe(this::handlerResponse,this::handlerError);
}
private void handlerResponse(List<String> strings) {
System.out.println(strings);
}
private void handlerError(Throwable throwable) {
Log.d("Error ","Response Error "+throwable.getMessage());
}
Can anyone help me to solve?
One more question please...Can I have an example to catch response error? Because I no receive any http status error, but only a null on console.
Related
I have the following java code that I'd like to use in an android app to query an api for continuous lat/lng changes of a device that is running a client app, I want to track the device. I believe the WebSocketCall method I'm attempting to use is deprecated. From what I can tell, there's a problem with how I'm trying to use the webSocket call to create the retrofit client and enqueue the data from the WebSocketListner into retrofit. I've researched several WebSocketListener examples and being a total n00b, I haven't been able to figure out the code. My idea is to keep the connection open to the api via WebSocket and process the data response using retrofit. Any assistance would be greatly appreciated.
private WebSocketCall webSocket;
private void createWebSocket() {
final MainApplication application = (MainApplication) getActivity().getApplication();
application.getServiceAsync(new MainApplication.GetServiceCallback() {
#Override
public void onServiceReady(final OkHttpClient client, final Retrofit retrofit, WebService service) {
User user = application.getUser();
map.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(user.getLatitude(), user.getLongitude()), user.getZoom()));
service.getDevices().enqueue(new WebServiceCallback<List<Device>>(getContext()) {
#Override
public void onSuccess(retrofit2.Response<List<Device>> response) {
for (Device device : response.body()) {
if (device != null) {
devices.put(device.getId(), device);
}
}
Request request = new Request.Builder().url(retrofit.baseUrl().url().toString() + "api/socket").build();
webSocket = WebSocketCall.create(client, request);
webSocket.enqueue(new WebSocketListener() {
#Override
public void onOpen(WebSocket webSocket, Response response) {
}
#Override
public void onFailure(IOException e, Response response) {
reconnectWebSocket();
}
#Override
public void onMessage(ResponseBody message) throws IOException {
final String data = message.string();
handler.post(new Runnable() {
#Override
public void run() {
try {
handleMessage(data);
} catch (IOException e) {
Log.w(MainFragment.class.getSimpleName(), e);
}
}
});
}
#Override
public void onClose(int code, String reason) {
reconnectWebSocket();
}
});
}
});
}
#Override
public boolean onFailure() {
return false;
}
});
}
So because I'm a total n00b it took some time and a lot of questions to figure this out. Maybe it'll help someone else in the future.
private WebSocket webSocket;
private void createWebSocket() {
final MainApplication application = (MainApplication) getActivity().getApplication();
application.getServiceAsync(new MainApplication.GetServiceCallback() {
#Override
public void onServiceReady(final OkHttpClient client, final Retrofit retrofit, WebService service) {
User user = application.getUser();
map.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(user.getLatitude(), user.getLongitude()), user.getZoom()));
service.getDevices().enqueue(new WebServiceCallback<List<Device>>(getContext()) {
#Override
public void onSuccess(retrofit2.Response<List<Device>> response) {
for (Device device : response.body()) {
if (device != null) {
devices.put(device.getId(), device);
}
}
Request request = new Request.Builder().url(retrofit.baseUrl().url().toString() + "api/socket").build();
Log.e("WebSockets", "Headers: " + request.headers().toString());
WebSocketListener webSocketListener = new WebSocketListener() {
private static final int NORMAL_CLOSURE_STATUS = 1000;
#Override
public void onOpen(WebSocket webSocket, Response response) {
webSocket.send("{Auth-Token:secret-api-token-here}");
Log.e("WebSockets", "Connection accepted!");
}
#Override
public void onFailure(#NotNull WebSocket webSocket, #NotNull Throwable t, #Nullable Response response) {
reconnectWebSocket();
}
#Override
public void onMessage(#NotNull WebSocket webSocket, #NotNull String text) {
final String data = text;
Log.e("WebSockets", "Receiving : " + text);
handler.post(new Runnable() {
#Override
public void run() {
try {
handleMessage(data);
} catch (IOException e) {
Log.w(MainFragment.class.getSimpleName(), e);
}
}
});
}
#Override
public void onMessage(WebSocket webSocket, ByteString bytes) {
Log.e("WebSockets", "Receiving bytes : " + bytes.hex());
}
#Override
public void onClosing(WebSocket webSocket, int code, String reason) {
webSocket.close(NORMAL_CLOSURE_STATUS, null);
Log.e("WebSockets", "Closing : " + code + " / " + reason);
}
#Override
public void onClosed(#NotNull WebSocket webSocket, int code, #NotNull String reason) {
reconnectWebSocket();
}
};
webSocket = client.newWebSocket(request, webSocketListener);
}
});
}
#Override
public boolean onFailure() {
return false;
}
});
}
I have multiple requests (upload files) into Observable and I want to execute them in parallel. The code is:
private void myMethod(List<String> filePathsList) {
List<Observable<String>> observables = new ArrayList<>();
for (String filePath : filePathsList) {
MultipartBody.Part multipartFile = getMultipartFile("some_file_name", filePath);
//here I'm just creating request from Retrofit restclient - the problem can't be here ;)
Observable<String> fileUploadObservable = UploadsRestClient.get().sendFile(multipartFile, "another_post_param");
observables.add(fileUploadObservable);
}
Observable<String> combinedObservable = Observable.zip(observables, new FuncN<String>() {
#Override
public String call(Object... args) {
return null;
}
});
combinedObservable.observeOn(AndroidSchedulers.mainThread())
.subscribeOn(Schedulers.io())
.subscribe(new Subscriber<String>() {
#Override
public void onCompleted() {
//called at the end
}
#Override
public void onError(Throwable throwable) {
//called if error occurs
}
#Override
public void onNext(String string) {
//should be called foreach request, but it's called only after the last one
}
});
}
The problem is that onNext() is called only after the last call is done, before onCompleted(),how can I get triggered after each request?
I have a function searchForTrips() which sends an API request and fetch some response in following way.
private void searchForTrips(){
int departurePortId = PORT_ID_LIST.get(departurePort);
int returnPortId = PORT_ID_LIST.get(returnPort);
int pax= Integer.parseInt(noOfPassengers);
String departureDatePARSED = DEPARTURE_DATE_VALUES.get(departureDate);
String returnDatePARSED = RETURN_DATE_VALUES.get(departureDate);
Call<TripSearchResponse> call = apiService.searchAvailableTrips(TripType,departurePortId,returnPortId,departureDatePARSED,returnDatePARSED,pax);
call.enqueue(new Callback<TripSearchResponse>() {
#Override
public void onResponse(Call<TripSearchResponse> call, Response<TripSearchResponse> response) {
int statusCode = response.code();
switch(statusCode){
case 200:
default:
Snackbar.make(findViewById(android.R.id.content),"Error loading data. Network Error.", Snackbar.LENGTH_LONG).show();
break;
}
}
#Override
public void onFailure(Call<TripSearchResponse> call, Throwable t) {
Log.i(TAG, t.getMessage());
Snackbar.make(findViewById(android.R.id.content),"Error loading data. Network Error.", Snackbar.LENGTH_LONG).show();
}
});
}
The purpose is to make this callback function reusable so I can call it from several activities and get requested data as I need. What is the best way to implement this?
try this way, its dynamic way and easy to use:
Create Retforit Interface:
public interface ApiEndpointInterface {
#Headers("Content-Type: application/json")
#POST(Constants.SERVICE_SEARCH_TRIP)
Call<JsonObject> searchForTrip(#Body TripRequest objTripRequest);
}
Create Retrofit Class:
public class AppEndPoint {
private static Retrofit objRetrofit;
public static ApiEndpointInterface getClient() {
if (objRetrofit == null){
objRetrofit = new Retrofit.Builder()
.baseUrl(Constants.SERVER_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return objRetrofit.create(ApiEndpointInterface.class);
}
}
Create this helper Classes/Interfaces to hold web service callback:
public enum ResponseState {
SUCCESS,
FAILURE,
NO_CONNECTION
}
public enum RequestType {
SEARCH_FOR_TRIP // add name for each web service
}
public class Response {
public ResponseState state;
public boolean hasError;
public RequestType requestType;
public JsonObject result;
}
public interface RestRequestInterface {
void Response(Response response);
Context getContext();
}
public class ResponseHolder { used to hold the Json response could be changed as your response
#SerializedName("is_successful")
#Expose
private boolean isSuccessful;
#SerializedName("error_message")
#Expose
private String errorMessage;
public boolean isSuccessful() {
return isSuccessful;
}
public void setSuccessful(boolean successful) {
isSuccessful = successful;
}
public String getErrorMessage() {
return errorMessage;
}
public void setErrorMessage(String errorMessage) {
this.errorMessage = errorMessage;
}
}
public class AppClient {
private static ApiEndpointInterface objApiEndpointInterface;
private static Response objResponse;
private static Call<JsonObject> objCall;
// implement new method like below for each new web service
public static void searchForTrip(TripRequest objTripRequest, RestRequestInterface objRestRequestInterface) {
objResponse = new Response();
objResponse.state = ResponseState.FAILURE;
objResponse.hasError = true;
objResponse.requestType = RequestType.SEARCH_FOR_TRIP; // set type of the service from helper interface
objApiEndpointInterface = AppEndPoint.getClient();
objCall = objApiEndpointInterface.searchForTrip(objTripRequest);
handleCallBack(objRestRequestInterface);
}
private static void handleCallBack(final RestRequestInterface objRestRequestInterface) {
objCall.enqueue(new Callback<JsonObject>() {
#Override
public void onResponse(Call<JsonObject> call, retrofit2.Response<JsonObject> response) {
try {
ResponseHolder objResponseHolder = new Gson().fromJson(response.body(), ResponseHolder.class);
if (objResponseHolder.isSuccessful()) {
objResponse.state = ResponseState.SUCCESS;
objResponse.hasError = false;
objResponse.result = response.body();
} else {
objResponse.errorMessage = objResponseHolder.getErrorMessage();
}
objRestRequestInterface.Response(objResponse);
} catch (Exception objException) {
objResponse.errorMessage = objRestRequestInterface.getContext().getString(R.string.server_error);
objRestRequestInterface.Response(objResponse);
}
}
#Override
public void onFailure(Call<JsonObject> call, Throwable objThrowable) {
String errorMessage = "";
if (objThrowable instanceof IOException) {
errorMessage = objRestRequestInterface.getContext().getString(R.string.no_connection_error);
} else {
errorMessage = objRestRequestInterface.getContext().getString(R.string.server_error);
}
objResponse.errorMessage = errorMessage;
objRestRequestInterface.Response(objResponse);
}
});
}
}
then go to your activity of fragment and make the call like this:
public class MainActivity extends AppCompatActivity implements RestRequestInterface {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// initialize ids
// prepare to call web service
// 1.Initialize your object to be sent over web service
TripRequest objTripRequest = new TripRequest();
objTripRequest.id = 1;
// 2.Show loader
// 3.Make the call
AppClient.searchForTrip(objTripRequest, this);
}
#Override
public void Response(Response response) {
// hide loader
try {
if (response.state == ResponseState.SUCCESS && !response.hasError) {
// check the type of web service
if (response.requestType == RequestType.SEARCH_FOR_TRIP) {
// acces the return here from response.result
}
} else {
String errorMsg = response.hasError ? response.errorMessage : getString(R.string.no_connection_error);
// show the error to the user
}
} catch (Exception objException) {
// show the error to the user
}
}
#Override
public Context getContext() {
// do not forgit set the context here
// if fragment replace with getAcitvity();
return this;
}
}
Since I got some bad reviews I am rewriting this question...
I have an HTTP REST server and a client (Android app). I have programmed several APIs that work just fine, however there is one that is giving me a 400 error, and if I put a breakpoint in the server, it does not even triggers it. So, I would like to understand why it fails :( ...
It is very simple, I have a value object called Alarm with a few attributes, that I want to POST to the server for registration of object in the database.
This is the output:
Callback failure for call to http://10.0.0.3:8080/...
java.io.IOException: Unexpected code Response{protocol=http/1.1, code=400, message=, url=http://10.0.0.3:8080/BiTrack_API/api/assets/registerAlarm}
at it.bitrack.fabio.bitrack.AlarmView$2$1.onResponse(AlarmView.java:438)
at okhttp3.RealCall$AsyncCall.execute(RealCall.java:135)
at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
This is my client side Android button listener:
View.OnClickListener addAlarmAction = new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
alarm.setThreshold(Float.parseFloat(thresholdEditText.getText().toString()));
String alarmJson = j.makeJsonBodyForAlarmRegistration(alarm);
tagLinearLayout.setVisibility(view.GONE);
operatorLinearLayout.setVisibility(view.GONE);
thresholdLinearLayout.setVisibility(view.GONE);
assetSpinner.setSelection(0);
r.attemptAddNewAlarm(alarmJson,
new Callback() {
#Override public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
#Override public void onResponse(Call call, Response response) throws IOException {
try (final ResponseBody responseBody = response.body()) {
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
Headers responseHeaders = response.headers();
for (int i = 0, size = responseHeaders.size(); i < size; i++) {
System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
}
final String responseBodyString = responseBody.string();
final int resultCode = response.code();
try {
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
Log.i("BiTrack", "attemptAddNewAlarm RESULT: " + resultCode);
executeAlarmRegistration(resultCode);
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
};
This is the code where I generate the Json body for the POST in the client:
public String makeJsonBodyForAlarmRegistration (Alarm alarm) {
Gson gson = new Gson();
String jsonAlarm = gson.toJson(alarm);
return jsonAlarm;
}
This is the actual POST code in the client (Android) side:
public void attemptAddNewAlarm(String json, Callback callback) throws Exception {
final OkHttpClient client = new OkHttpClient();
RequestBody body = RequestBody.create(JSON, json);
Request request = new Request.Builder()
.url(WEB_SERVER + "BiTrack_API/api/assets/registerAlarm")
.post(body)
.build();
client.newCall(request).enqueue(callback);
}
This is my server side code:
#POST
#Path("/registerAlarm")
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public Response registerAlarm(Alarm alarm) {
System.out.println("Received API Call: registerAlarm for alarm tagId: " + alarm.getTagId() + " operatorId: " + alarm.getOperatorId() + " treshold: " + alarm.getThreshold());
DataProcessor dp = new DataProcessor();
AssetUpdateDAO aDAO = new AssetUpdateDAO();
ArrayList<Alarm> customerAlarms = aDAO.getUserAlarmsForAsset(alarm.getUserId(), alarm.getAssetId());
if (dp.isNewAlarmDuplicate(customerAlarms, alarm)) {
return Response.status(480).build(); // duplicated error
} else {
int response = aDAO.insertAssetUserAlarm(alarm.getUserId(), alarm.getAssetId(), alarm.getTagId(), alarm.getOperatorId(), alarm.getThreshold());
if (response == -5) {
return Response.status(484).build(); // something went wrong while inserting alarm into db
} else {
return Response.status(200).build();
}
}
}
This is my Alarm value object (identical class in client and server):
public class Alarm {
public Alarm() {
}
protected int id;
protected int userId;
protected int assetId;
protected int tagId;
protected int operatorId;
protected float threshold;
protected String networkAssetCode;
public String getNetworkAssetCode() {
return networkAssetCode;
}
public void setNetworkAssetCode(String networkAssetCode) {
this.networkAssetCode = networkAssetCode;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public int getAssetId() {
return assetId;
}
public void setAssetId(int assetId) {
this.assetId = assetId;
}
public int getTagId() {
return tagId;
}
public void setTagId(int tagId) {
this.tagId = tagId;
}
public int getOperatorId() {
return operatorId;
}
public void setOperatorId(int operatorId) {
this.operatorId = operatorId;
}
public float getThreshold() {
return threshold;
}
public void setThreshold(float threshold) {
this.threshold = threshold;
}
}
I really appreciate any help...
In order to help you, the endpoint code is required. Now it is even unclear what technology stack is used for your API.
But from the information that is present... The endpoint considers your json as invalid.
400 Bad Request
The request could not be understood by the server due to malformed
syntax. The client SHOULD NOT repeat the request without
modifications.
In jax-rs the payload is first deserialized before it reaches the method that is bound to the url en http method.
Possibly the deserializing is failing and it never reaches the breakpoint you set.
What would be interesting is the following:
logs or exception from the server. The client exception is not that helpful, since the server returns this response.
the actual (json) payload that is send over the wire.
what deserialization mechanism is used at the server end? Reflection or did you make your own deserializer?
I found the issue! After 48 hours looking for the impossible, discovered that I had done a small update at the object attribute at the server side that had not been replicated in the client side...
I was trying to use netflix observable however I managed to do so only synchronously:
This is how I define the remote call:
#Named
public class BroConsumerService {
..
#HystrixCommand(fallbackMethod = "stubbedMethod")
public Observable<String> executeObservableBro(String name) {
return new ObservableResult<String>() {
#Override
public String invoke() {
return executeRemoteService(name);
}
};
}
private String stubbedMethod(String name) {
return "return stubbed";
}
//here I am actually invoking (and observing this method)
#RequestMapping("/executeObservableBro")
public String executeObservableBro(#RequestParam(value = "name", required = false) String name) throws ExecutionException, InterruptedException {
Observable<String> result= broConsumerService.executeObservableBro(name);
result.subscribe(new Observer<String>() {
#Override
public void onCompleted() {
System.out.println("completed");
}
#Override
public void onError(Throwable e) {
System.out.printf(e.getMessage());
}
#Override
public void onNext(String s) {
System.out.println("on next..");
}
});
}
But that works synchronously. I want to be able to "listen" to the executeObservableBro before I execute it. and each time it's being executed ill get notified.
Example would be highly appreciated.
Thanks,
ray.
you have to provide schedulers in subscribeOn method like:
public static void main(String[] args) throws InterruptedException {
Observable<Integer> observable2 = Observable.create(subscriber->{
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Arrays.asList(1, 2, 3).forEach((value)-> subscriber.onNext(value));
subscriber.onCompleted();
subscriber.onError(new RuntimeException("error"));
});
System.out.println("Before");
observable2
.subscribeOn(Schedulers.io()).subscribe(
(next) -> log.info("Next element {}", next),
(error) -> log.error("Got exception", error),
() -> log.info("Finished")//on complete
);
System.out.println("After");
//Thread.sleep(5000); //uncomment this to wait for subscriptions, otherwise main will quit
}
Its not async by default :)