在ViewPager上跨几个片段加载Json，需要更好的方法

Question

Developer advisory: The following content might hurt the sensibility of some developers, please read it at your own risks.

I'm beginning in Android developement / java, and my goal is to load a json from a remote rest service, and use it across 2 fragments on a ViewPager, currently i'm doing it this way (please read developer advisory :) , i just show the important part of the code here, in an algorythmic way, no need to check syntax):

---

I declare a variable on the viewpager, that i plan to call back using getActivity from fragment

Viewpager.java

public class Viewpager extends AppCompatActivity{
    ...
    public static JSONObjInvitationParser jsonParser;
    ...
}

Fragment1.java

public class Fragment1  extends ListFragment{
    ...

 public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    final Viewpager activity = (Viewpager) getActivity();
    activity.jsonParser = CallMyRestServiceAndGetTheJSON();
    populateListView(activity.jsonParser.getanOtherListArrayOfSTuff());
     }
}

On the second fragment, i can't call my activy.jsonParser during onCreatView of course, otherwise i get pointerNull, my guess is that the Viewpager is Calling all the createView at once, so does the setUserVisibleHint hack.

Fragment2.java

public class Fragment2  extends ListFragment{
   ...

   @Override
   public void setUserVisibleHint(boolean isVisibleToUser) {
       super.setUserVisibleHint(isVisibleToUser);
        final Viewpager activity = (Viewpager) getActivity();
       if (isVisibleToUser) {
           System.out.println(activity.jsonParser.getListArrayOfSTuff());
           populateListView(activity.jsonParser.getListArrayOfSTuff());
        }
    }
    ...

    }
}

Like this, it works, and i can acutally populate my listvews on my 2 fragments calling only once the rest service, but there must be a wayyyy better way than this ugly hack :/ Unfortunately, i don't know it yet, anyone could let me know how he would implement properly that ?

thanks a lot in advance :)

Answer 1

I often create a model class to represent JSON data. That class implement Parcelable interface. And you can put your data to Fragment:

DetailsFragment f = new DetailsFragment();

Bundle args = new Bundle();
args.putParcelable("data", yourDataObject);
f.setArguments(args);