java - Garbage value in jtable after adding row dynamically -

i have jtable has few columns.in have jcombobox. @ program start want them empty.i have 1 jbutton on click action of button have code add row dynamically in table.

but after adding row garbage value in cell having jcombobox. shown in below figure :

and here code :

code add jcombobox in table

// create columns names string columnnames[] = { "item", "sun item", "required quantity","price","gross amount" };  // create data final string datavalues[][] =     {         { "", "", "","","", },     };      tablemodel = new defaulttablemodel(datavalues, columnnames);      // create new table instance     table = new jtable( tablemodel );  updateitemcombo(); tablecolumn itemcolumn = table.getcolumnmodel().getcolumn(0); itemcolumn.setcelleditor(new defaultcelleditor(comboitem));  public void updateitemcombo(){     vector<string> s = new vector<string>();     try{         setconnectin();         string str = "select * itemtable";         stmt = conn.createstatement();         rs = stmt.executequery(str);         while(rs.next())         {             string nm = rs.getstring("item_name");             s.add(nm);         }         conn.close();     }catch(exception e2){         e2.printstacktrace();     }     defaultcomboboxmodel<string> modeldata = new defaultcomboboxmodel<string>(s);     comboitem.setmodel(modeldata); } 

code add row dynamically on button click :

 btnaddorder.addactionlistener(new actionlistener() {     public void actionperformed(actionevent arg0) {             tablemodel.addrow(datavalues);             tablemodel.firetabledatachanged();         }     });   

what should remove garbage value table? please help

the addrow(...) method takes 1-dimensional array parameter. attempting add 2-dimensional array.

also, not use:

tablemodel.firetabledatachanged(); 

it job of tablemodel invoke appropriate firexxx() method, way in case firetablerowsinserted(...).