App crash on using RecyclerView

Question

I am using RecyclerView in my app. My application crashes with the following error

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView$LayoutManager.onMeasure(android.support.v7.widget.RecyclerView$Recycler, android.support.v7.widget.RecyclerView$State, int, int)' on a null object reference

While searching on stackoverflow I found that this error usually comes when layoutmanager was not added. But I have added the layout manager. Please help me find what is causing this crash.

Edit - Code for the fragment using Recyclerview

public class FeedFragment extends Fragment implements HJAppConstants {

    private RecyclerView mRecyclerView;

    private FeedRecyclerAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.hj_feed_layout, null);
        mRecyclerView = (RecyclerView) view
                .findViewById(R.id.feeds_recycler_view);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        LinearLayoutManager layoutManager = new LinearLayoutManager(
                getActivity());
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        mRecyclerView.setLayoutManager(layoutManager);
        mAdapter = new FeedRecyclerAdapter();
        mRecyclerView.setAdapter(mAdapter);
        addData();

    }

    /**
     * Adds static data
     */
    private void addData() {
        ArrayList<HJFeedItemObject> itemObjs = new ArrayList<HJFeedItemObject>();
        itemObjs.add(new HJFeedItemObject(HJ_FEED_TYPE_PHOTO,
                "potala_palace.jpg", "This is an article about Potala Palace",
                "Thu 7, 07:45pm", new HJUserObject("Umesh", "")));
        itemObjs.add(new HJFeedItemObject(HJ_FEED_TYPE_PRODUCT, "pokhara.jpg",
                "A beautiful place to visit - Pokhara ", "Thu 7, 07:45pm",
                new HJUserObject("Umesh", "")));
        itemObjs.add(new HJFeedItemObject(HJ_FEED_TYPE_ARTICLE, "patan.jpg",
                "A Tourist attraction - Patan", "Thu 7, 07:45pm",
                new HJUserObject("Umesh", "")));
        itemObjs.add(new HJFeedItemObject(HJ_FEED_TYPE_PHOTO,
                "potala_palace.jpg", "This is an article about Potala Palace",
                "Thu 7, 07:45pm", new HJUserObject("Umesh", "")));
        itemObjs.add(new HJFeedItemObject(HJ_FEED_TYPE_PRODUCT, "pokhara.jpg",
                "A beautiful place to visit - Pokhara ", "Thu 7, 07:45pm",
                new HJUserObject("Umesh", "")));
        itemObjs.add(new HJFeedItemObject(HJ_FEED_TYPE_ARTICLE, "patan.jpg",
                "A Tourist attraction - Patan", "Thu 7, 07:45pm",
                new HJUserObject("Umesh", "")));
        mAdapter.addData(itemObjs);
    }

i take it this is a fragment and thus moving the code from onActivityCreated to onViewCreated should solve the issue — LeMoN.xaH, Feb 23 '15 at 12:44
I moved the content to onViewCreated but still having the same problem. — umesh lohani, Feb 23 '15 at 12:54
have you moved the onActivityCreated code to onViewCreated or just put it in the onCreateView, the onActivityCreated just tells the fragment that the activity is done with its own onCreate, it does not mean that the fragment has been created yet. — LeMoN.xaH, Feb 23 '15 at 12:54
See the given link same issue I can resolve using this link: http://stackoverflow.com/q/27416834/1896677 — Bhavikkumar, Aug 06 '15 at 09:01

score 0 · Answer 1 · answered Feb 23 '15 at 21:01

This issue occurs when no LayoutManager was provided for the RecyclerView.

Change your code, and move the layoutManager setup to onCreateView.

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState){

   View view = inflater.inflate(R.layout.hj_feed_layout, null);
   mRecyclerView = (RecyclerView) view
                .findViewById(R.id.feeds_recycler_view);

   LinearLayoutManager layoutManager = new LinearLayoutManager(
                getActivity());
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        mRecyclerView.setLayoutManager(layoutManager);

   return view;
}

App crash on using RecyclerView

1 Answers1