如何实现 RxJava 的链式调用 -- map 方法的实现

Api.java

public interface Api{
    void queryPhoto(String query,QueryCallback QueryCallback);
    interface QueryCallback{
        void onQuerySuccess(List<Photo> photoList);
        void onQueryFailed(Exception e);
    }
}

PhotoUtils.java

public class PhotoUtils{
    Api mApi;
    public void handlePhotoSync(){
        mApi.queryPhoto("flyer", new Api.QueryCallback() {
            @Override
            public void onQuerySuccess(List<Photo> photoList) {
                Photo photo = getBestPhoto(photoList);
              	String imgUrl = photo.getUrl();
            }

            @Override
            public void onQueryFailed(Exception e) {
				ToastUtils.show(e);
            }
        });
    }
}

=================================

异步里面还有异步方法，flatMap 待续

=================================