响应为 400 错误时，Retrofit2 崩溃

Question

i'm using retrofit2 and Rxjava

the crash occured when application recieved 400 error code response but i don't know where to handling error

interface "IMyService"

@POST("api/account/signin")
@FormUrlEncoded
io.reactivex.Observable<String> login(@Field("email") String email,
                                                   @Field("password") String password);

Retrofit Client

i add some interceptor for cookie but without interceptor, results are same

public class RetrofitClient {
    
    private static Retrofit instance = null;
    
    public static Retrofit getInstance(Context context) {
        AddCookiesInterceptor in1 = new AddCookiesInterceptor(context);
        ReceivedCookiesInterceptor in2 = new ReceivedCookiesInterceptor(context);
        
        OkHttpClient okHttpClient = new OkHttpClient.Builder ()
                .addNetworkInterceptor(in1)
                .addInterceptor(in2)
                .build ();

        if (instance==null) {
            instance = new Retrofit.Builder()
                    .baseUrl("http://192.168.0.31:3070/")
                    .client(okHttpClient)
                    .addConverterFactory(ScalarsConverterFactory.create())
                    .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                    .build();
        }
        return instance;
    }
}

Retrofit, Rxjava

Retrofit retrofitClient = RetrofitClient.getInstance(this);
iMyService = retrofitClient.create(IMyService.class);

compositeDisposable.add(iMyService.login(email, password)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Consumer<String>() {
                    @Override
                    public void accept(String response) throws Exception {
                         //....
           }));

where can i handling error for 400 response?

and error

Caused by: retrofit2.adapter.rxjava2.HttpException: HTTP 401 Unauthorized
    at retrofit2.adapter.rxjava2.BodyObservable$BodyObserver.onNext(BodyObservable.java:54)
    at retrofit2.adapter.rxjava2.BodyObservable$BodyObserver.onNext(BodyObservable.java:37)
    at retrofit2.adapter.rxjava2.CallExecuteObservable.subscribeActual(CallExecuteObservable.java:43)
    at io.reactivex.Observable.subscribe(Observable.java:10981)
    at retrofit2.adapter.rxjava2.BodyObservable.subscribeActual(BodyObservable.java:34)
    at io.reactivex.Observable.subscribe(Observable.java:10981)

sorry for my english skill

Answer 1

try:

compositeDisposable.add(iMyService.login(email, password)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(
                        new Consumer<String>() {
                            @Override
                            public void accept(String response) throws Exception {
                                //....
                            }
                        },
                        new Consumer<Throwable>() {
                            @Override
                            public void accept(Throwable throwable) throws Exception {
                                // handle the error here
                                Log.e("LOGIN_ERROR", "", throwable);
                                if ((throwable instanceof HttpException && ((HttpException) throwable).code() == 401)
                                || (throwable.getCause() instanceof HttpException && ((HttpException) throwable.getCause()).code() == 401)) {
                                    // handle 401 error specifically
                                }
                            }
                        });

Answer 2

Your API is returning an error to your Observable and your code snipppet does not have the Rx error handler implemented hence the crash. You can change it to something like this:

compositeDisposable.add(iMyService.login(email, password)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Observer<Void>() {
                 @Override
                 public void onCompleted() {
                 // May be ignored
                 }

                 @Override
                 public void onError(Throwable error) {
                 // check error type and handle here
                 if (error instanceof HttpException) // handle all kinds of Http errors
                 }

                 @Override
                 public void onNext(String response) {
                 // consume results
                 }
             });