Save custom object on screen rotate in Fragment or Activity

Question

I know this question is very common and I have read so many different answers but none fits in my problem. In my application, I have an activity and in rhye activity I load a fragment. I also send some data(in the form of Bundle) to the fragment. So my Problem is when the screen is rotated, I save the fragment in onSaveInstanceState Activity method and check in onCreate Method weather savedInstance is null or not and on that basis I load the fragment. Activity code :

 @Override
public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
    super.onSaveInstanceState(outState, outPersistentState);
    outState.putParcelable(Const.TAG_REQ_CUSTOM,DetailsItems);
    outState.putString(Const.TAG_FLOW, Const.TAG_MAIN_FLOW);
    getSupportFragmentManager().putFragment(outState,"current_fragment",fragment);
}

onCreate Method :

if (findViewById(R.id.fragment_frame) != null) {
        if (savedInstanceState != null) {
// this invoke when screen rotate but the app crash 

            DetailsItems = savedInstanceState.getParcelable(Const.TAG_REQ_CUSTOM);
            String flow = savedInstanceState.getString(Const.TAG_FLOW);
           ft = getSupportFragmentManager().getFragment(savedInstanceState,"current_fragment");
            mFragmentManager=getSupportFragmentManager();
            mFragmentTransaction = mFragmentManager.beginTransaction();
            bundle= new Bundle();
            bundle.putString(Const.TAG_FLOW, flow);
            bundle.putParcelable(Const.TAG_REQ_BOOKING_DETAILS, bookingDetailsItems);
            ft.setArguments(bundle);
            mFragmentTransaction.replace(R.id.fragment_frame, ft).commit();
        }else{
           // load fragment on first time
        }
    }

So my Question is: Where do I have to save the custom Object(in parent Activity or in fragment) ? When my saved Instance is not null than app crashesh and logs is :

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference

Answer 1

use this code in Activity :

    if (findViewById(R.id.fragment_frame) != null) {
        if (savedInstanceState != null) {
fragment =getSupportFragmentManager().getFragment(savedInstanceState,"current_fragment");

        }else{
           // load fragment on first time
        }
    }

and in fragment :

//save custom object

 @Override
    public void onSaveInstanceState(Bundle outState){
        super.onSaveInstanceState(outState);
        outState.putParcelable("key",customObject);
    }

//now retrieve here

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    if (savedInstanceState != null)
    customObject= savedInstanceState.getParcelable("key");
}