No Adapter Attached Skipping layout error with RecyclerView Adapter

Question

These are steps I am doing in this project:

• First I am creating a user profile on Firebase
• Once the profile is created, I am redirecting the user to another activity, where the user is creating a journal with Image
• Then saving the journal with image on Firestore
• Once the data is created on the user profile, I am trying to fetch the values from Firestore using RecyclerView Adapter
• Then on a listing page I am trying to fetch all the values in an ArrayList--> here I am getting the error of No Adapter Attached

The ArrayList Activity file:

• Initializing the recyclerView in OnCreate

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_journal_list);
  
        firebaseAuth= FirebaseAuth.getInstance();
        user= firebaseAuth.getCurrentUser();
  
        noJournalEntry= findViewById(R.id.list_no_thoughts);
        journalList= new ArrayList<>();
  
        recyclerView= (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setHasFixedSize(true);
  
  
    }
  

• Invoking the RecyclerView in onStart:

   @Override
   protected void onStart() {
       super.onStart();
       //we are getting the user Id of the person who is logged in
       collectionReference.whereEqualTo("userId", JournalApi.getInstance()
               .getUserId())
               .get()
               .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
           @Override
           public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
               if(!queryDocumentSnapshots.isEmpty()) {
                   for(QueryDocumentSnapshot journals: queryDocumentSnapshots){
                       Journal journal = journals.toObject(Journal.class);
                       journalList.add(journal);
  
                      Toast.makeText(JournalListActivity.this,"UserId found", Toast.LENGTH_LONG).show();
                   }
  
                   // Invoke Recyclerview
  
                   journalRecyclerAdapter= new JournalRecyclerAdapter(JournalListActivity.this, journalList);
                   recyclerView.setAdapter(journalRecyclerAdapter);
                   journalRecyclerAdapter.notifyDataSetChanged();
  
               } else {
  
                   noJournalEntry.setVisibility(View.VISIBLE);
  
               }
           }
       }).addOnFailureListener(new OnFailureListener() {
           @Override
           public void onFailure(@NonNull Exception e) {
  
               Toast.makeText(JournalListActivity.this,"UserId NOT found", Toast.LENGTH_LONG).show();
  
           }
       });
  
  
   }
  

  }

As you can see that the RecyclerView is called fine, but the ArrayList is not loading.

The Error: E/RecyclerView: No adapter attached; skipping layout

I referred to various posts in Stackoverflow and followed the steps, not sure where I am going wrong.

I am adding screenshots here of the Arraylist file:

The RecyclerView adapter:

Answer 1

You are getting the following warning, not an error:

E/RecyclerView: No adapter attached; skipping layout

Because you are setting the adapter in a background thread. To solve this, you have to set the adapter outside the callback and inside it, just notify it about the changes. So please move the following lines of code:

journalRecyclerAdapter= new JournalRecyclerAdapter(JournalListActivity.this, journalist);
recyclerView.setAdapter(journalRecyclerAdapter);

Right after:

super.onStart();

And leave the following line as it is inside the callback:

journalRecyclerAdapter.notifyDataSetChanged();

And the warning will disapear.