Auto check Checkbox on comparing the values from json

I want to check the roll and roll check days if they are equal then auto check that check box and can also un-check that if need by user.

1.)Check if roll and rollcheck data from Json are equal then check the check box automatically.

2.)If needed by user ..user can also uncheck that automatically checked checkbox

MainActivity.java

public class MainActivity extends AppCompatActivity {

    Toolbar toolbar;
    FloatingActionButton fab;
    ListView list;
    TextView txt_menu;
    String dipilih;
    private static final String TAG = MainActivity.class.getSimpleName();

    Adapter adapter;
    ProgressDialog pDialog;

    List<Data> itemList = new ArrayList<Data>();


    private static String url = "http://url.php";

    public static final String TAG_NAMA = "nama";
     public static final String TAG_ROLL = "roll";
    public static final String TAG_ROLLCheck = "rollcheck";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        fab     = (FloatingActionButton) findViewById(R.id.fab);
        list    = (ListView) findViewById(R.id.list_menu);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String checkbox = "";
                for (Data hold : adapter.getAllData()) {
                    if (hold.isCheckbox()) {
                        checkbox += "\n" + hold.getMenu();
                    }
                }
                if (!checkbox.isEmpty()) {
                    dipilih = checkbox;
                } else {
                    dipilih = "Anda Belum Memilih Menu.";
                }

                formSubmit(dipilih);
            }
        });

        callVolley();

        adapter = new Adapter(this, (ArrayList<Data>) itemList);
        list.setAdapter(adapter);

        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
                adapter.setCheckBox(position);
            }
        });

    }

    private void formSubmit(String hasil){
        AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        LayoutInflater inflater = getLayoutInflater();
        View dialogView = inflater.inflate(R.layout.form_submit, null);
        dialog.setView(dialogView);
        dialog.setIcon(R.mipmap.ic_launcher);
        dialog.setTitle("title");
        dialog.setCancelable(true);

        txt_menu = (TextView) dialogView.findViewById(R.id.txt_menu);

        txt_menu.setText(hasil);

        dialog.setNeutralButton("CLOSE", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });

        dialog.show();
    }

    private void callVolley(){
        itemList.clear();
        // menapilkan dialog loading
        pDialog = new ProgressDialog(this);
        pDialog.setMessage("Loading...");
        showDialog();

        // membuat request JSON
        JsonArrayRequest jArr = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        Log.d(TAG, response.toString());
                        hideDialog();

                        // Parsing json
                        for (int i = 0; i < response.length(); i++) {
                            try {
                                JSONObject obj = response.getJSONObject(i);

                                Data item = new Data();

                                item.setMenu(obj.getString(TAG_NAMA));

                                 item.setRoll(obj.getString(TAG_ROLL));
                                item.setRollCheck(obj.getString(TAG_ROLLCheck));

                                // menambah item ke array
                                itemList.add(item);
                            } catch (JSONException e) {
                                e.printStackTrace();
                            }
                        }

                        // notifikasi adanya perubahan data pada adapter
                        adapter.notifyDataSetChanged();
                    }
                }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d(TAG, "Error: " + error.getMessage());
                hideDialog();
            }
        });

        // menambah request ke request queue
        AppController.getInstance().addToRequestQueue(jArr);
    }

    private void showDialog() {
        if (!pDialog.isShowing())
            pDialog.show();
    }

    private void hideDialog() {
        if (pDialog.isShowing())
            pDialog.dismiss();
    }

}

Adapter.java

public class Adapter extends BaseAdapter {

    private Context activity;
    private ArrayList<Data> data;
    private static LayoutInflater inflater = null;
    private View vi;
    private ViewHolder viewHolder;

    public Adapter(Context context, ArrayList<Data> items) {
        this.activity = context;
        this.data = items;
        inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        return data.size();
    }

    @Override
    public Object getItem(int i) {
        return i;
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int position, View view, ViewGroup viewGroup) {
        vi = view;
        final int pos = position;
        Data items = data.get(pos);

        if(view == null) {
            vi = inflater.inflate(R.layout.list_row, null);
            viewHolder = new ViewHolder();
            viewHolder.checkBox = (CheckBox) vi.findViewById(R.id.cb);
            viewHolder.menu = (TextView) vi.findViewById(R.id.nama_menu);
            viewHolder.roll = (TextView) vi.findViewById(R.id.roll);
            vi.setTag(viewHolder);
        }else {
            viewHolder = (ViewHolder) view.getTag();
            viewHolder.menu.setText(items.getMenu());
            viewHolder.roll.setText(items.getRoll());
        }

        if(items.isCheckbox()){
            viewHolder.checkBox.setChecked(true);
        } else {
            viewHolder.checkBox.setChecked(false);
        }

        return vi;
    }

    public ArrayList<Data> getAllData(){
        return data;
    }

    public void setCheckBox(int position){
        Data items = data.get(position);
        items.setCheckbox(!items.isCheckbox());
        notifyDataSetChanged();
    }

    public class ViewHolder{
        TextView roll;
        TextView menu;
        CheckBox checkBox;
    }
}

Data.java

public class Data {
    private String roll;
    private String menu;
    private boolean check;
    private String roll_check;
    public Data() {}

    public Data(String roll,String menu, boolean check,String roll_check) {
        this.roll=roll;
        this.menu = menu;
        this.check = check;
        this.roll_check = roll_check;
    }

    public String getRoll() {
        return roll;
    }

    public void setRoll(String roll) {
        this.roll = roll;
    }

    public String getRollCheck() {
        return roll_check;
    }

    public void setRollCheck(String roll_check) {
        this.roll_check = roll_check;
    }






    public String getMenu() {
        return menu;
    }

    public void setMenu(String menu) {
        this.menu = menu;
    }

    public boolean isCheckbox() {
        return check;
    }

    public void setCheckbox(boolean check) {
        this.check = check;
    }
}