Sorting integer in jtable

when i click the 'Price' radiobutton it sorts the Price Row but in this order

• 1
• 11
• 12
• 13
• 2
• 21
• 200
• 3
• 32
• 300

how can i fix it? im still new in java. please help me. thanks. :D

rdbtnNewRadioButton_2.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            DefaultRowSorter sorter = ((DefaultRowSorter)table.getRowSorter());
            List <RowSorter.SortKey> sortKeys = new ArrayList<RowSorter.SortKey>();
            sortKeys.add(new RowSorter.SortKey(4, SortOrder.ASCENDING));
            sorter.setSortKeys(sortKeys); 

        }
    });

• override getColumnClass in your XxxTableModel, default class is String, the your result from RowSorter is correct

• use Integer.Class