如何刷新Retrofit2 / rxJava中的ACCESS-TOKEN

时间:2017-12-27 16:56:46

标签: java android rx-java retrofit2

我提出请求(任何,授权,注册等),然后我发现我需要更新ACCESS-TOKEN,也就是说,我收到错误401

这是授权请求:

BaseApplication.getApiClient()
            .signIn(accessToken, body)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new SingleObserver<UserProfile>() {
                @Override
                public void onSubscribe(Disposable d) {
                    Log.d("-- SignInOnSubscribe", "Subscribed!");
                }

                @Override
                public void onSuccess(UserProfile userProfile) {
                    if (userProfile.getErrorDetails() != null) {
                        onSignInFinishedCallback.onLoginFailure(userProfile.getErrorDetails());
                        Log.d("-- SignInOnError", userProfile.getErrorDetails());
                    } else {
                        onSignInFinishedCallback.onLoginSuccess(userProfile);
                        profileRepository.updateUserProfile(userProfile);

                        Log.d("-- SignInOnSuccess", userProfile.getName());
                    }
                }

                @Override
                public void onError(Throwable e) {
                    Log.d("-- SignInOnError", e.getMessage());

                    if (e.getMessage().equals(Constants.CODE_UNAUTHORIZED)){
                        // Action on error 401
                    }

                    onSignInFinishedCallback.onLoginFailure(e.getMessage());
                }
            });

API请求:

@POST("/api/login")
Single<UserProfile> getAccessToken(@Body Map<String, String> requestBody);

@POST("/api/abonent/login")
Single<UserProfile> signIn(@Header("X-ACCESS-TOKEN") String accessToken,
                             @Body Map<String, String> requestBody);

例如,授权请求为request 1,接收TOKEN的请求为query 2

问题:如果我在TOKEN中收到错误并在query 1成功后返回query 2,我该如何更新query 1

1 个答案:

答案 0 :(得分:0)

我不确定您是如何收到新令牌的,因为getAccessToken()的返回类型是Single<UserProfile>。我想它应该是Single<String>。也许情况并非如此,您会在标题或UserProfile字段中收到令牌。在任何一种情况下,您都可以从下面的解决方案中获得一个想法,并根据您的情况进行调整。

方法是我们从原始的observable创建一个新的observable,它使用一个令牌存储,它包含最新的令牌。我们使用composeonErrorResumeNext处理401错误,以便进行令牌刷新请求,新令牌保存到令牌存储中,并且此次使用新令牌重试原始请求。 / p>

有关更详细的说明,请参阅以下代码中的注释:

public void signIn(final Map<String, String> body) {
    Single
            // Wrap the original request with a "defer" so that the access token is
            // evaluated each time it is called. This is important because the refreshed
            // access token should be used the second time around.
            .defer(new Callable<SingleSource<UserProfile>>() {
                @Override
                public SingleSource<UserProfile> call() throws Exception {
                    return BaseApplication.getApiClient()
                            .signIn(accessTokenStore.getAccessToken(), body);
                }
            })
            // Compose it with a transformer that refreshes the token in the token store and
            // retries the original request, this time with the refreshed token.
            .compose(retryOnNotAuthorized(body))

            // The code remains the same from here.
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new SingleObserver<UserProfile>() {
                @Override
                public void onSubscribe(Disposable d) {
                    Log.d("-- SignInOnSubscribe", "Subscribed!");
                }

                @Override
                public void onSuccess(UserProfile userProfile) {
                    if (userProfile.getErrorDetails() != null) {
                        onSignInFinishedCallback.onLoginFailure(userProfile.getErrorDetails());
                        Log.d("-- SignInOnError", userProfile.getErrorDetails());
                    } else {
                        onSignInFinishedCallback.onLoginSuccess(userProfile);
                        profileRepository.updateUserProfile(userProfile);

                        Log.d("-- SignInOnSuccess", userProfile.getName());
                    }
                }

                @Override
                public void onError(Throwable e) {
                    Log.d("-- SignInOnError", e.getMessage());

                    if (e.getMessage().equals(Constants.CODE_UNAUTHORIZED)) {
                        // Action on error 401
                    }

                    onSignInFinishedCallback.onLoginFailure(e.getMessage());
                }
            });
}

@NonNull
private SingleTransformer<UserProfile, UserProfile> retryOnNotAuthorized(final Map<String, String> body) {
    return new SingleTransformer<UserProfile, UserProfile>() {
        @Override
        public SingleSource<UserProfile> apply(final Single<UserProfile> upstream) {
            // We use onErrorResumeNext to continue our Single stream with the token refresh
            // and the retrial of the request.
            return upstream.onErrorResumeNext(new Function<Throwable, SingleSource<? extends UserProfile>>() {
                @Override
                public SingleSource<UserProfile> apply(Throwable throwable) throws Exception {
                    if (throwable instanceof HttpException
                            && ((HttpException) throwable).code() == 401) {
                        return BaseApplication.getApiClient().getAccessToken(body)
                                // I always use doOnSuccess() for non-Rx side effects, such as caching the token.
                                // I think it's clearer than doing the caching in a map() or flatMap().
                                .doOnSuccess(new Consumer<String>() {
                                    @Override
                                    public void accept(String accessToken) throws Exception {
                                        // Save the access token to the store for later use.
                                        accessTokenStore.storeAccessToken(accessToken);
                                    }
                                })
                                // We don't need the result of getAccessToken() any more, so I
                                // think it's cleaner to convert the stream to a Completable.
                                .toCompletable()

                                // After the token is refreshed and stored, the original request
                                // should be repeated.
                                .andThen(upstream);
                    }

                    // If the error was not 401, pass through the original error
                    return Single.error(throwable);
                }
            });
        }
    };
}

更新:令牌存储只是一个带get和store方法的常规接口。您应该将其实现为POJO(将令牌存储在字段中),或者您可以将令牌存储在共享首选项中,以便令牌在应用程序重新启动后仍然存在。