Removing element from adapter throws Index out of bound exception

Question

I have two recycler views. The first recyclerview is basically a list of data where I can choose an item and its quantity and I am storing this chosen item data into a map. The second one is the list of the selected data. which I am generating from getting the values() from the map. The second one also has similar viewholder and I can change the quantity there also. One the quantity reaches zero I remove the item from the list and try to notifydatasetChanged().

The problem is the removing of an item from the second list is not working properly and the app crashes with error

java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid view holder adapter positionViewHolder

I am using a listener interface on my first Recycler so that when the quantity is changed and the item is added to the map. The adapter of the second recycler is notified of the changes. below is the code i am using to update the second recycler view.

public void updateList(){
        mMap = ((UserMainActivity)getActivity()).getItemMap();

        inputs.clear();
       // adapter.notifyDataSetChanged();

        adapter = new MyCartAdapter(inputs,getContext());
        cartList.setAdapter(adapter);
        for(AllItems t:mMap.values()) {
              inputs.add(t);
        }
        adapter.notifyDataSetChanged();
    }

Below is my second recycler view's adapter. Where I am changing the quantities of the selected items.

public class MyCartAdapter  extends RecyclerView.Adapter<MyCartAdapter.MyCartViewHolder>{
private List<AllItems> listItems1;
private Context context;
private Typeface typeface;



public MyCartAdapter(List<AllItems> listItems1, Context context) {
    this.listItems1 = listItems1;
    this.context = context;
}

@NonNull
@Override
public MyCartAdapter.MyCartViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.cart_items_layout, parent, false);

    return new MyCartViewHolder(v);
}

@Override
public void onBindViewHolder(@NonNull final MyCartAdapter.MyCartViewHolder holder, final int position) {

    final AllItems orderItem = listItems1.get(position);
    holder.setProductImage(orderItem.getImageUrl(),context);
    holder.name.setText(orderItem.getName());
    String price = String.valueOf(orderItem.getPrice());
    holder.price.setText(price);

    final HashMap<String, AllItems> items = ((UserMainActivity)context).getItemMap();
    holder.counter.setText(orderItem.getQuantity());

    holder.add.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String quantity = String.valueOf(holder.counter.getText());
            int count = Integer.parseInt(quantity)+1;
            holder.counter.setText(String.valueOf(count)); 
            String url = orderItem.getImageUrl();
            AllItems newitem = new AllItems(orderItem.getName(),orderItem.getComname(),url, String.valueOf(count),orderItem.getWeight,orderItem.getPrice());
            ((UserMainActivity)context).addItem(orderitemname,newitem);
          //  notifyItemChanged(position);
        }
    });
//counter text iitem.textview showing the quantity of the selected item . integer count returns the value of counter text below i am checking if its zero than it simply sets the value to zero and else reduce it and update the map.
    holder.minus.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String counterText = String.valueOf(holder.counter.getText());
            int count = Integer.parseInt(counterText);
            if (count==0){
                holder.counter.setText("0");
            }
            if (count==1){
                holder.counter.setText("0");
                AllItems item = items.get(orderItem.getName());
                if (item!=null){
                    String orderit = orderItem.getName();
                    ((UserMainActivity)context).removeItem(orderit);
// here i am removing the value from the list which throws the exception 
                    listItems1.remove(position);
                      notifyItemRemoved(position);
                }
            }
            if (count>1){
                String quantity = String.valueOf(count-1);
                holder.counter.setText(quantity);
                String orderitemname = orderItem.getName();
                String url = orderItem.getImageUrl();
                String weight = "100";
                long weightl = Long.parseLong(weight);
                AllItems newitem = new AllItems(orderItem.getName(),orderItem.getComname(),url, quantity,weight,orderItem.getPrice());
                ((UserMainActivity)context).addItem(orderitemname,newitem);
             //   listItems1.set(position, newitem);
             //   notifyItemChanged(position);

            }
        }
    });

}

@Override
public int getItemCount() {
    return listItems1.size();
}



public class MyCartViewHolder extends RecyclerView.ViewHolder {
    public TextView name,price,count,comname;
    public TextView weight;
    LinearLayout add,minus;
    TextView counter;

    public MyCartViewHolder(View itemView) {
        super(itemView);
        name = (TextView) itemView.findViewById(R.id.ProName);
        price = (TextView) itemView.findViewById(R.id.proPrice);
        weight = (TextView) itemView.findViewById(R.id.ProWeight);
        counter = (TextView) itemView.findViewById(R.id.counter);
        add = (LinearLayout) itemView.findViewById(R.id.addLin);
        minus= (LinearLayout) itemView.findViewById(R.id.minusLin);
    }

    public void setProductImage(final String thumb_image, final Context ctx){
        productImage = (ImageView) itemView.findViewById(R.id.ProImage);
        Picasso.with(ctx).setIndicatorsEnabled(false);
        Picasso.with(ctx)
                .load(thumb_image)
                .networkPolicy(NetworkPolicy.OFFLINE)
                .placeholder(R.drawable.basket_b).into(productImage, new Callback() {
            @Override
            public void onSuccess() {
            }
            @Override
            public void onError() {
                Picasso.with(ctx).load(thumb_image).placeholder(R.drawable.basket).into(productImage);
            }
        });
 }
    public void setComname(String name){
        comname = (TextView)itemView.findViewById(R.id.proComName);
        comname.setText(name);
    }
}
}

Answer 1

This jumps out at me:

listItems1.remove(position);
notifyItemChanged(position);

The notifyItemChanged() method exists to tell the adapter that the data at the given position has changed, and that the ViewHolder should be re-bound. This is not what you're doing; you're removing an item.

Probably your app is crashing because you're removing the last item in your data set (e.g. position 10) and then telling the adapter that the item at position 10 has changed... but now the maximum position in your data set is 9.

Instead, you should use the notifyItemRemoved() method.

listItems1.remove(position);
notifyItemRemoved(position);