我已经对这个特定的问题进行了彻底的搜索，但是在我遇到的每个问题下实现答案时，仍然得到相同的输出：

End of input at line 1 column 1 path $

我在PostMan上执行了请求，得到了预期的输出：Here is the Screenshot of the Postman Request

接口

@POST(Constant.API_REQUEST)
    Observable<ServerResponse> postToWinnersList(@Body ServerRequest serverRequest);

Api客户端

public class ApiClient {
    public static Retrofit retrofit;

    private static OkHttpClient.Builder okHttpClientBuilder;
    private static HttpLoggingInterceptor loggingInterceptor;

    public static Retrofit getApiClient(){
        if (retrofit == null){
//            create instance of Httpclient
            okHttpClientBuilder = new OkHttpClient.Builder();
            loggingInterceptor = new HttpLoggingInterceptor();
            loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

            if(BuildConfig.DEBUG){
                okHttpClientBuilder.addInterceptor(loggingInterceptor);
            }
//            instance of retrofit
            retrofit = new Retrofit.Builder().baseUrl(Constant.BASE_URL).
                    addCallAdapterFactory(RxJava2CallAdapterFactory.create()).
                    addConverterFactory(GsonConverterFactory.create())
                    .client(okHttpClientBuilder.build())
                    .build();
        }
        return retrofit;
    }
}

改装/RxJava请求代码：

Observable<ServerResponse> response = apiInterface.postToWinnersList(serverRequest);
                response.observeOn(AndroidSchedulers.mainThread())
                        .subscribeOn(Schedulers.io())
                        .subscribeWith(new DisposableObserver<ServerResponse>() {
                            @Override
                            public void onNext(ServerResponse serverResponse) {
                                AVLoadingIndicatorView1.setVisibility(View.GONE);
                                txtSubmitWinner.setVisibility(View.VISIBLE);
                            }

                            @Override
                            public void onError(Throwable e) {
                                AVLoadingIndicatorView1.setVisibility(View.GONE);
                                txtSubmitWinner.setVisibility(View.VISIBLE);
                                Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
                            }

                            @Override
                            public void onComplete() {
                                showShortMsg(getString(R.string.submit_success));
                            }
                        });

请帮忙，先谢了。