获取错误IllegalArgumentException：无法在Android中为retrofit2.Call创建调用适配器

Question

我正在尝试在我的应用程序中实现OpenWeatherMap API，并且我在执行时遇到错误。

我的代码：

public class WeatherProvider {
private static WeatherService mWeatherService = null;

public interface WeatherService {
    @GET("APPID=" + API_KEY)
    Call<GetWeatherResponse> getWeather(@Query("lat") String latitude, @Query("lon") String longitude);
}

public static WeatherService getWeatherAPI(){

    if (mWeatherService == null){
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://api.openweathermap.org/data/2.5/weather?")
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        mWeatherService = retrofit.create(WeatherService.class);
    }
    return mWeatherService;
}}

对于示例URI调用：http://api.openweathermap.org/data/2.5/weather?lat=12.9176315&lon=77.5909999&APPID= {API + KEY}

当我尝试使用此代码调用WeatherAPI时

Call<GetWeatherResponse> call = WeatherProvider.getWeatherAPI()
                    .getWeather(String.valueOf(mLocationFetcher.fetchLatitude()),String.valueOf(mLocationFetcher.fetchLongitude()));
            call.enqueue(new Callback<GetWeatherResponse>() {
                @Override
                public void onResponse(Call<GetWeatherResponse> call, Response<GetWeatherResponse> response) {
                    Log.d(LOG_TAG, String.valueOf(response));
                }

                @Override
                public void onFailure(Call<GetWeatherResponse> call, Throwable t) {

                }
            });

我收到以下错误：

FATAL EXCEPTION: main
Process: com.simplicity.anuj.myday, PID: 28218
                                                                               java.lang.IllegalArgumentException: Unable to create call adapter for retrofit2.Call<com.simplicity.anuj.myday.Weather.GetWeatherResponse>
                                                                                   for method WeatherService.getWeather
                                                                                   at retrofit.Utils.methodError(Utils.java:177)
                                                                                   at retrofit.MethodHandler.createCallAdapter(MethodHandler.java:47)
                                                                                   at retrofit.MethodHandler.create(MethodHandler.java:26)
                                                                                   at retrofit.Retrofit.loadMethodHandler(Retrofit.java:151)
                                                                                   at retrofit.Retrofit$1.invoke(Retrofit.java:132)
                                                                                   at java.lang.reflect.Proxy.invoke(Proxy.java:813)
                                                                                   at $Proxy1.getWeather(Unknown Source)
                                                                                   at com.simplicity.anuj.myday.Activity.AddEntryActivity$3.onClick(AddEntryActivity.java:138)
                                                                                   at android.view.View.performClick(View.java:5637)
                                                                                   at android.view.View$PerformClick.run(View.java:22429)
                                                                                   at android.os.Handler.handleCallback(Handler.java:751)
                                                                                   at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                   at android.os.Looper.loop(Looper.java:154)
                                                                                   at android.app.ActivityThread.main(ActivityThread.java:6119)
                                                                                   at java.lang.reflect.Method.invoke(Native Method)
                                                                                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                                                                                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
                                                                                Caused by: java.lang.IllegalArgumentException: Could not locate call adapter for retrofit2.Call<com.simplicity.anuj.myday.Weather.GetWeatherResponse>. Tried:
                                                                                * retrofit.ExecutorCallAdapterFactory
                                                                                   at retrofit.Retrofit.nextCallAdapter(Retrofit.java:207)
                                                                                   at retrofit.Retrofit.callAdapter(Retrofit.java:175)
                                                                                   at retrofit.MethodHandler.createCallAdapter(MethodHandler.java:45)
                                                                                    ... 15 more

在我通过Callback调用API的部分。我哪里错了。请帮忙。 POJO类是使用jsonschema2pojo创建的。