Java.Lang.NullPointerException while using listview simple adapter

Question

I have a listview that shows two sqlite tables' values. First I tried to use ArrayAdapter to view them and all values were shown. But they looked messy, so I tried using a simple adapter. hHre is my code.

for(int i=0; i<= promo.size();i++){
    ProductModulePromo b =dataSource.getproductmodulepromo(moduleid);
    productmoduledesc = b.getProductmoduledesc().toString();
    producttype = b.getProducttype().toString();
    productpromo = b.getproductpromotion().toString();
    map1.put("three",productpromo);
    map1.put("two",producttype);
    map1.put("one",productmoduledesc);
    Globals.promo.add(map1);}

promo is my arraylist<productmodulepromo>() . when i try to compile those code. all values that shown are same. so i try to change with this code on datasource.java and use those arraylist on formpromo.java. here is my DBDatasource.java's code:

public ArrayList<HashMap<String, String>> getproduct1() {
    ArrayList<HashMap<String, String>> promo = new  ArrayList<HashMap<String, String>>();
    database  = dbHelper.getReadableDatabase();
    Cursor cursor = database.rawQuery("select productmodule.productmoduledescription, productdetail.producttype, productdetail.productpromotion from productmodule, productdetail where productmodule.productmoduleid=productdetail.productmoduleid", null);
            cursor.moveToFirst();
            if (cursor.moveToFirst()) {
                do {
                    productmoduledesc=cursor.getString(cursor.getColumnIndex(DBHelper.PRODUCT_MODULE_DESC));
                    producttype = cursor.getString(cursor.getColumnIndex(DBHelper.PRODUCT_TYPE));
                    productpromo = cursor.getString(cursor.getColumnIndex(DBHelper.PRODUCT_PROMOTION));
                    map1.put("one",productmoduledesc);
                    map1.put("two",producttype);
                    map1.put("three",productpromo);
                    promo.add(map1);    
                } while (cursor.moveToNext());
            }
            cursor.close();
    return promo;
  }

here is my Formpromo.java :

dataSource = new DBDataSource(this);
          dataSource.open();
          promo = dataSource.getproduct1(); 
          adapter = new SimpleAdapter(FormPromo.this, promo, R.layout.item_to,
                  new String[] {"one","two","three"},
                  new int[] {R.id.edtbrandto,R.id.edtqtyto,R.id.edtharga});
          setListAdapter(adapter);
          final ListView listpromo = (ListView) findViewById(android.R.id.list);
          setListAdapter(adapter);

and I am getting an error as Java.Lang.NullpointerException on map1.put("one",productmoduledesc); . I have no idea how to fix them all. Thanks for help. any help will be appreciated.

Answer 1

Seems like you never set map1, add it to the beginning of the loop, because else you'd overwrite the old values

like this

...
do {
    map1 = newHashMap<String, String>(); // add
    productmoduledesc=cursor.getString(cursor.getColumnIndex(DBHelper.PRODUCT_MODULE_DESC));
    producttype = cursor.getString(cursor.getColumnIndex(DBHelper.PRODUCT_TYPE));
    productpromo = cursor.getString(cursor.getColumnIndex(DBHelper.PRODUCT_PROMOTION));
    map1.put("one",productmoduledesc);
    map1.put("two",producttype);
    map1.put("three",productpromo);
    promo.add(map1);    
  } while (cursor.moveToNext());
...