如何使用RxAndroid和Retrofit 2检索响应体？

Question

我正在使用Retrofit 2(beta 4),我希望从使用标准Call响应转向RxAndroid Observable响应.我成功地通过简单的交换Call<List<ExampleObject>>来切换我的大部分呼叫Observable<List<ExampleObject>>.我的一些电话使用Call<okhttp3.ResponseBody>,效果很好,但当我换掉时Call,我遇到了一个错误:

03-03 15:21:44.237 27333-27333/com.example.app E/AndroidRuntime: FATAL EXCEPTION: main
        Process: com.example.app, PID: 27333
        java.lang.IllegalArgumentException: Unable to create call adapter for rx.Observable<okhttp3.ResponseBody>
            for method AuthenticationService.getLoginForm
            at retrofit2.Utils.methodError(Utils.java:119)
            at retrofit2.MethodHandler.createCallAdapter(MethodHandler.java:52)
            at retrofit2.MethodHandler.create(MethodHandler.java:25)
            at retrofit2.Retrofit.loadMethodHandler(Retrofit.java:164)
            at retrofit2.Retrofit$1.invoke(Retrofit.java:145)
            at java.lang.reflect.Proxy.invoke(Proxy.java:393)
            at $Proxy6.getLoginForm(Unknown Source)
            at com.example.app.ui.fragment.LoginFragment.login(LoginFragment.java:214)
            at com.example.app.ui.fragment.LoginFragment.lambda$onContinue$1(LoginFragment.java:168)
            at com.example.app.ui.fragment.LoginFragment.access$lambda$1(LoginFragment.java)
            at com.example.app.ui.fragment.LoginFragment$$Lambda$4.onClick(Unknown Source)
            at android.view.View.performClick(View.java:5204)
            at android.view.View$PerformClick.run(View.java:21153)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:148)
            at android.app.ActivityThread.main(ActivityThread.java:5417)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
        Caused by: java.lang.IllegalArgumentException: Could not locate call adapter for rx.Observable<okhttp3.ResponseBody>.
         Tried:
          * retrofit2.ExecutorCallAdapterFactory
           at retrofit2.Retrofit.nextCallAdapter(Retrofit.java:230)
           at retrofit2.Retrofit.callAdapter(Retrofit.java:194)
           at retrofit2.MethodHandler.createCallAdapter(MethodHandler.java:50)
              ... 18 more

我ResponseBody像往常一样使用而不是另一个对象的原因是因为在这些情况下我需要解析HTML,据我所知,HTML解析器没有Retrofit转换器.我知道我可能自己创建一个,但我宁愿不用我需要解析的少量HTML.

我的问题是为什么ResponseBodyRetrofit 2本身不支持Retrofit 2 RxJava Adapter ？有没有其他方法可以从一个Observable？获取响应字符串？

---

我的服务:

public interface AuthenticationService() {

    @GET("cas/login")
    Observable<Response<ResponseBody>> login();
}

相关的改造代码:

public static Retrofit getRetrofit() {
    if(mRetrofit == null) {
        return new Retrofit.Builder()
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .addConverterFactory(GsonConverterFactory.create(getGson()))
                .client(getOkHttpClient())
                .build();
    } return mRetrofit;
}

public static AuthenticationService getAuthenticationService() {
    return getRetrofit().create(AuthenticationService.class);
}

响应尝试:

private void login() {
    RestClient.getAuthenticationService().login()
            .observeOn(ASchedulers.newThread())
            .subscribeOn(AndroidSchedulers.mainThread())
            .doOnNext(this::onLoginResponse);
}

private void onLoginResponse(Response<ResponseBody>> response) {
    try {
        parseResponse(response.body().string());
    } catch (IOException) {
        Timber.w(throwable, "Failed to login");
    }
}

新堆栈跟踪:

03-03 16:14:57.848 26866-26866/com.example.app E/AndroidRuntime: FATAL EXCEPTION: main
        Process: com.example.app, PID: 26866
        java.lang.IllegalArgumentException: Unable to create call adapter for rx.Observable<retrofit2.Response<okhttp3.ResponseBody>>
            for method AuthenticationService.getLoginForm
            at retrofit2.Utils.methodError(Utils.java:119)
            at retrofit2.MethodHandler.createCallAdapter(MethodHandler.java:52)
            at retrofit2.MethodHandler.create(MethodHandler.java:25)
            at retrofit2.Retrofit.loadMethodHandler(Retrofit.java:164)
            at retrofit2.Retrofit$1.invoke(Retrofit.java:145)
            at java.lang.reflect.Proxy.invoke(Proxy.java:393)
            at $Proxy3.getLoginForm(Unknown Source)
            at com.example.app.ui.fragment.LoginFragment.login(LoginFragment.java:206)
            at com.example.app.ui.fragment.LoginFragment.lambda$onContinue$1(LoginFragment.java:160)
            at com.example.app.ui.fragment.LoginFragment.access$lambda$1(LoginFragment.java)
            at com.example.app.ui.fragment.LoginFragment$$Lambda$4.onClick(Unknown Source)
            at android.view.View.performClick(View.java:5204)
            at android.view.View$PerformClick.run(View.java:21153)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:148)
            at android.app.ActivityThread.main(ActivityThread.java:5417)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
        Caused by: java.lang.IllegalArgumentException: Could not locate call adapter for rx.Observable<retrofit2.Response<okhttp3.ResponseBody>>.
         Tried:
          * retrofit2.ExecutorCallAdapterFactory
           at retrofit2.Retrofit.nextCallAdapter(Retrofit.java:230)
           at retrofit2.Retrofit.callAdapter(Retrofit.java:194)
           at retrofit2.MethodHandler.createCallAdapter(MethodHandler.java:50)
              ... 18 more

Answer 1

尝试这样的事情:

import okhttp3.ResponseBody;
import retrofit2.Response;

@GET("/whatever")
Observable<Response<ResponseBody>> getWhatever();

编辑:不要忘记你必须为RxJava指定适配器:

    new Retrofit.Builder()
            ...
            .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
            .build()
            .create(Api.class);