Dagger 生成改造拦截器的多个实例

我是 Dagger 和 Retrofit 的新手。我遇到的问题是，尽管在 dagger 模块中声明了单例，但仍生成了多个改造自定义拦截器实例。我只需要一个实例。

匕首模块

@Module
public class ApiModule
{
    private Config config;

    public ApiModule(Config config) {
        this.config = config;
    }

    @Provides @Singleton
    public OkHttpClient.Builder provideOkHttpClient()
    {
        return new OkHttpClient.Builder();
    }

    @Provides @Singleton
    public AuthenticationRequestInterceptor provideRequestInterceptor()
    {
        return new AuthenticationRequestInterceptor();
    }

    @Provides @Singleton
    public Retrofit provideRetrofitInstance()
    {
        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        // set your desired log level
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);

        OkHttpClient.Builder httpClient = new OkHttpClient.Builder();

        // add session headers interceptor
        httpClient.addInterceptor(provideRequestInterceptor());

        // add logging as last interceptor
        httpClient.addInterceptor(logging);  

        return new Retrofit.Builder()
                .baseUrl(getConfig().getBaseUrl())
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .client(httpClient.build()) //for logging purpose remove later
                .build();
    }
}

改装拦截器

public class AuthenticationRequestInterceptor implements Interceptor
{
    private Map<String, String> defaultHeaders;

    public AuthenticationRequestInterceptor()
    {
        this.defaultHeaders = new HashMap<>();
    }

    public void setDefaultHeaders(Map<String, String> headers)
    {
        this.defaultHeaders = headers;
    }

    @Override
    public Response intercept(Chain chain) throws IOException
    {
        Request request = chain.request();

        Request.Builder requestBuilder = request.newBuilder();

        for (String key: this.defaultHeaders.keySet())
        {
            requestBuilder.addHeader(key, this.defaultHeaders.get(key));
        }

        return chain.proceed(requestBuilder.build());
    }
}

连接器

public class Connect
{
    @Inject Retrofit retrofit;
    @Inject Config config;
    @Inject AuthenticationRequestInterceptor headerInterceptor;

    public Connect(PercentApp application)
    {
        ((PercentApp) application).getComponent().inject(this);

/** 在这里设置拦截器标头，但这会在不同的地方设置 实例比稍后在 postUser **/ 中调用的实例

     headerInterceptor.setDefaultHeaders(generateDefaultAuthHeaders());
    }

    public void postUser(Observer observer, User user)
    {
        if(retrofit != null)
        {
            ApiServices api = retrofit.create(ApiServices.class);
            Observable<HashMap> observable = api.postUser("{post something}");
            observable.
                    subscribeOn(Schedulers.io())
                    .observeOn(AndroidSchedulers.mainThread())
                    .subscribe(observer);
        }
    }

}

在我的应用程序中，我创建了 Dagger 实例，如下所示：

DaggerApplicationComponent.builder()
                .applicationModule(new ApplicationModule(this))
                .apiModule(new ApiModule(new Config(environment)))
                .build();

在我的 MainActivity 中我创建 Connect 实例

Connect connect = new Connect((MyApp) getApplication());
User user = new User();
connect.postUser(new UserObserver(this), user);

现在的问题是 AuthenticationRequestInterceptor 构造函数被调用两次，我不明白为什么，因为我设置的标头设置为拦截器的不同实例。请帮忙。谢谢

你不应该打电话provideRequestInterceptor直接地

@Provides @Singleton
public Retrofit provideRetrofitInstance(AuthenticationRequestInterceptor authInterceptor)
{
    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
    // set your desired log level
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);

    OkHttpClient.Builder httpClient = new OkHttpClient.Builder();

    // add session headers interceptor
    httpClient.addInterceptor(authInterceptor);

    // add logging as last interceptor
    httpClient.addInterceptor(logging);  

    return new Retrofit.Builder()
            .baseUrl(getConfig().getBaseUrl())
            .addConverterFactory(GsonConverterFactory.create())
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .client(httpClient.build()) //for logging purpose remove later
            .build();
}