Getting ArrayIndex out of Bounds Exception when adding new items to list while scrolling

Question

I have a ListView in which I load data from SQLite by setting a limit of 3 data from SQLite when scrolling the list I have used AsyncTask to load another 3 data from the database, but when the new data is loaded it shows me an error: ArrayIndexOutOfBoundsException.

Adapter:

public class FarmerAdapter extends BaseAdapter implements Filterable{
    Context context;
    ArrayList<Farmer> farmeritems;
    ArrayList<Farmer> mStringFilterList;
    ValueFilter valueFilter;

    public FarmerAdapter(Context context, ArrayList<Farmer> list) {

        this.context = context;
        farmeritems = list;
        mStringFilterList = list;
    }


    @Override
    public int getCount() {

        return farmeritems.size();
    }

    @Override
    public Object getItem(int position) {

        return farmeritems.get(position);
    }

    @Override
    public long getItemId(int position) {

        return position;
    }

    @Override
    public int getViewTypeCount() {

        return getCount();
    }

    @Override
    public int getItemViewType(int position) {

        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup arg2) {
        Farmer farmerdetails = farmeritems.get(position);

        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.model_farmer, null);

        }


        final TextView farmname = (TextView) convertView.findViewById(R.id.tv_farmer_name);
        final TextView farmmobno = (TextView) convertView.findViewById(R.id.tv_farmer_mobno);
        final TextView farmlocation = (TextView) convertView.findViewById(R.id.tv_farmer_location);
        final LinearLayout farmtrade = (LinearLayout) convertView.findViewById(R.id.li_farmer_trade);
        final LinearLayout farmadvance = (LinearLayout) convertView.findViewById(R.id.li_farmer_advance);
        final ImageView img_trade = (ImageView)convertView.findViewById(R.id.img_farmertrade);
        final ImageView img_advance = (ImageView)convertView.findViewById(R.id.img_farmeradvance);
        farmname.setText(farmerdetails.getFarmername());
        farmmobno.setText(farmerdetails.getFarmermobno());
        farmlocation.setText(farmerdetails.getFarmerlocation());
        farmtrade.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                img_trade.setColorFilter(ContextCompat.getColor(context, R.color.colorAccent));
                img_advance.clearColorFilter();
                Intent b = new Intent(context, Farmer_simpletrade_Activity.class);
                b.putExtra("fname", farmname.getText().toString());
                b.putExtra("fmobno", farmmobno.getText().toString());
                context.startActivity(b);
            }
        });
        farmadvance.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                img_advance.setColorFilter(ContextCompat.getColor(context, R.color.colorAccent));
                img_trade.clearColorFilter();
                Intent c = new Intent(context, Farmer_simpleadvance_Activity.class);
                c.putExtra("farmername", farmname.getText().toString());
                c.putExtra("farmermobno", farmmobno.getText().toString());
                context.startActivity(c);
                ((Activity) context).finish();
            }
        });
        convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //todo disable the comments for farmer individual transaction

                Intent a = new Intent(context, FarmerLedgerView_Activity.class);
                a.putExtra("farmername", farmname.getText().toString());
                a.putExtra("farmermobno", farmmobno.getText().toString());
                context.startActivity(a);
                ((Activity) context).finish();

            }
        });
        return convertView;

    }

    @Override
    public Filter getFilter() {
        if (valueFilter == null) {
            valueFilter = new ValueFilter();
        }
        return valueFilter;
    }

    private class ValueFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new FilterResults();

            if (constraint != null && constraint.length() > 0) {
                ArrayList<Farmer> filterList = new ArrayList<Farmer>();
                for (int i = 0; i < mStringFilterList.size(); i++) {
                    if ((mStringFilterList.get(i).getFarmername().toUpperCase())
                            .contains(constraint.toString().toUpperCase())) {

                        Farmer farmer = new Farmer(mStringFilterList.get(i)
                                .getFarmername(), mStringFilterList.get(i)
                                .getFarmermobno(), mStringFilterList.get(i)
                                .getFarmerlocation());

                        filterList.add(farmer);
                    }
                }
                results.count = filterList.size();
                results.values = filterList;
            } else {
                results.count = mStringFilterList.size();
                results.values = mStringFilterList;
            }
            return results;

        }

        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {
            farmeritems = (ArrayList<Farmer>) results.values;
            notifyDataSetChanged();
        }

    }

    public void setTransactionList(ArrayList<Farmer> newList) {
        farmeritems = newList;
        notifyDataSetChanged();
    }
}

AsyncTask to load data from background:

  private class LoadDataTask extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {

    }

    @Override
    protected Void doInBackground(Void... params) {

        if (isCancelled()) {
            return null;
        }

        // Simulates a background task
        try {
            Thread.sleep(1000);
            offSet=offSet+3;
            if (offSet > totalcount) {
               loadingMore=false;
            } else {
                Log.e("OffsetNo", String.valueOf(offSet));
                databasehandler = new DatabaseHandler(getApplicationContext());

                farmerlabels = new ArrayList<Farmer>();
                String selectQuery = "SELECT * FROM farmercontactlabel ORDER BY farmername COLLATE NOCASE LIMIT " + offSet + "";
                SQLiteDatabase db = databasehandler.getReadableDatabase();
                Cursor cursor = db.rawQuery(selectQuery, null);
                if (cursor.moveToFirst()) {
                    do {
                        Farmer farmerdetails = new Farmer();
                        farmerdetails.setFarmername(cursor.getString(1));
                        farmerdetails.setFarmermobno(cursor.getString(2));
                        farmerdetails.setFarmerlocation(cursor.getString(3));
                        list.add(farmerdetails);

                    } while (cursor.moveToNext());

                }
                cursor.close();
                db.close();

            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }



        return null;

    }

    @Override
    protected void onPostExecute(Void result) {

        fadapter.setTransactionList(list);
        list_farmer.onLoadMoreComplete();

       // fadapter.notifyDataSetChanged();

        super.onPostExecute(result);
    }

    @Override
    protected void onCancelled() {
        // Notify the loading more operation has finished
        list_farmer.onLoadMoreComplete();
    }
}

Database Structure:

 String CREATE_FARMERS_TABLE = "CREATE TABLE " + FARMERCONTACT_LABELS + "("
            + FARMER_ID + " INTEGER,"
            + FARMER_NAME + " TEXT,"
            + FARMER_MOBNO + " NUMERIC PRIMARY KEY,"
            + FARMER_LOCATION + " TEXT" + ");";
    db.execSQL(CREATE_FARMERS_TABLE);

Database:

 public ArrayList<Farmer> getAllfarmers(int offset) {
    ArrayList<Farmer> farmerlabels = new ArrayList<Farmer>();
    String selectQuery = "SELECT * FROM " + FARMERCONTACT_LABELS + " ORDER BY farmername COLLATE NOCASE LIMIT " + offset + "";
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
        do {
            Farmer farmerdetails = new Farmer();
            farmerdetails.setFarmername(cursor.getString(1));
            farmerdetails.setFarmermobno(cursor.getString(2));
            farmerdetails.setFarmerlocation(cursor.getString(3));
            farmerlabels.add(farmerdetails);
        } while (cursor.moveToNext());
    }
    cursor.close();
    db.close();
    return farmerlabels;
}

Error:

java.lang.ArrayIndexOutOfBoundsException: length=3; index=3
at android.widget.AbsListView$RecycleBin.addScrapView(AbsListView.java:7103)
at android.widget.ListView.layoutChildren(ListView.java:1653)
at android.widget.AbsListView.onLayout(AbsListView.java:2230)
at android.view.View.layout(View.java:16001)
at android.view.ViewGroup.layout(ViewGroup.java:5181)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1195)
at android.view.View.layout(View.java:16001)

Answer 1

If you're limiting the number of rows to 3, the last index will be 2. So If you try to get by the index 3, you'll get NullPointerException.