SearchView with GridView in the Postexecute Method

Question

Before you guys make it duplicate, I have searched for it everywhere and I am stuck at a point where I need your expertise.

I am calling my data in a doInBackground method and storing the values in a SimpleAdapter and In the postExecute method, I am assigning the adapter to my gridView. And also in the PostExecute I have a searchView method that filters my adapter.

Now, when I press any letter in the search my App Crashes with a NullPointerException and if the same code I run on same thread without making an AsyncTask I do not get this error. Here is my code of DoInBackground:

protected Void doInBackground(Void... voids) {

        try{
            connect = CONN(un, passwords, db, ip);
            String StoredProc = "{call pro.DocumentDelivery_inst_update_delete(?,?)}";
            callableStatement=connect.prepareCall(StoredProc);
            callableStatement.setString(1, "Select");
            callableStatement.setString(2, MainActivity.usernam);
            rs = callableStatement.executeQuery();

            while(rs.next()){
                Map<String,String> datanum = new HashMap<String, String>();
                datanum.put("B",rs.getString("FullName"));
                datanum.put("C",rs.getString("Name"));
                datanum.put("D",rs.getString("DocumentType"));
                datanum.put("A",rs.getString("Id"));
                datanum.put("E",rs.getString("TaskType"));
                datanum.put("F",rs.getString("Comments"));
                datanum.put("G",rs.getString("Tasktime"));
                datanum.put("H",rs.getString("Priority"));
                datanum.put("I",rs.getString("Telephone"));
                data.add(datanum);
            }

            String [] from = {"A","B","C","D","E","F","G","H","I"};
            int[] views = {R.id.doc_grid_t4,R.id.doc_grid_t1, R.id.doc_grid_t2,R.id.doc_grid_t3,R.id.doc_grid_t5,R.id.doc_grid_t6,R.id.doc_grid_t7,R.id.doc_grid_t8,R.id.doc_grid_t9};
            ADA = new SimpleAdapter(document_Pro_List.this,data,R.layout.custom_pro_document_view, from, views);


            synchronized (this) {
                int counter = 0;
                while(counter<=4){
                    this.wait(100);
                    counter++;
                    publishProgress(counter*25);
                }
            }
        }
        catch (InterruptedException | SQLException e){
            e.printStackTrace();
        }
        return null;

    }

and this is my code for postExecute method:

protected void onPostExecute(Void result){
        sv = (SearchView) findViewById(R.id.searchView);
        progressDialog.dismiss();
        gridView.setAdapter(ADA);
        sv.setOnQueryTextListener(new SearchView.OnQueryTextListener() {

            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String query) {
                ADA.getFilter().filter(query);
                //ADA.notifyDataSetChanged();
                return false;
            }
        });

}

NOTE: the moment I take out this

Map<String,String> datanum = new HashMap<String, String>();

out of while loop I stop getting the NullPointerException BUT this does not help me because it then repeats the 1st data from the database to all the next ones. Also I know I should work with WebAPI and I am doing that side by side. Please help me out on how I can remove this Exception.

THANK YOU

Answer 1

So I figured it out, I sometimes had an empty value in my

datanum.put("D",rs.getString("DocumentType"));

and because this went Null the searchView couldn't handle that one Null value and gave a NullPointerException.