java - Attempt to get length of null array - retrieve bitmap image from sqlite DB -

i trying retrieve image sqlite database. image stored blob , trying retrieve using array. i'm not sure why doing this. permissions set correctly.

package com.example.joao_.quizathonegroupteamproject.activity;  import android.content.context; import android.graphics.bitmap; import android.graphics.bitmapfactory; import android.view.layoutinflater; import android.view.view; import android.view.viewgroup; import android.widget.baseadapter; import android.widget.imageview; import android.widget.textview;  import com.example.joao_.quizathonegroupteamproject.databaseclasses.user; import com.example.joao_.quizathonegroupteamproject.r;  import java.util.arraylist;  /**  * created quoc nguyen on 13-dec-16.  */  public class userlistadapter extends baseadapter {      private context context;     private  int layout;     private arraylist<user> foodslist;      public userlistadapter(context context, int layout, arraylist<user> foodslist) {         this.context = context;         this.layout = layout;         this.foodslist = foodslist;     }      @override     public int getcount() {         return foodslist.size();     }      @override     public object getitem(int position) {         return foodslist.get(position);     }      @override     public long getitemid(int position) {         return position;     }      private class viewholder{         imageview imageview;      }      @override     public view getview(int position, view view, viewgroup viewgroup) {          view row = view;         viewholder holder = new viewholder();          if(row == null){             layoutinflater inflater = (layoutinflater) context.getsystemservice(context.layout_inflater_service);             row = inflater.inflate(layout, null);               holder.imageview = (imageview) row.findviewbyid(r.id.imgfood);             row.settag(holder);         }         else {             holder = (viewholder) row.gettag();         }          user food = foodslist.get(position);          byte[] tblusersimage = food.getimage();         bitmap bitmap = bitmapfactory.decodebytearray(tblusersimage, 0, tblusersimage.length);         holder.imageview.setimagebitmap(bitmap);          return row;     } } 

you can retrieve blob image , stored in byte array this:

byte[] array = cursor.getblob(columnindex);    bitmap bitmap = bitmapfactory.decodebytearray(array, 0 ,array.length); 

and set image view

holder.imageview.setimagebitmap(bitmap);