1) Edit your posting and delete all the code. Then add the code back in using the "Code tags" so the code retains its formatting and is readable.
i want to can put only double numbers with two decimals in cells.
a) first the getColumnClass() method should return Double.class, it you want to store a Double in the column. There is not need to override the setValueAt() method the editor will create the Double for you
b) Check out Table Format Renderers for some reusable renderers. The create a double renderer the code would be something like:
subject: Jtable double with 2 decimal and data validation