JCheckBox em uma Jtable

public void Obs()
    {   
        Date datOBS = null;
        String obs = "";
        DateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
        try {
            datOBS = new java.sql.Date(((java.util.Date) formatter.parse(d)).getTime());
        } catch (ParseException ex) {
            Logger.getLogger(consultaExtratos.class.getName()).log(Level.SEVERE, null, ex);
        }

            jcheck = new JCheckBox();

            DefaultTableCellRenderer cellRender = new DefaultTableCellRenderer();
            TextObs.getColumnModel().getColumn(1).setCellRenderer(cellRender);
            cellRender.setHorizontalAlignment(SwingConstants.CENTER);
            TableColumn colunaOBS = TextObs.getColumnModel().getColumn(1);
            colunaOBS.setCellEditor(new DefaultCellEditor(jcheck));

            obj_conexao.executeSQL("SELECT o.OBSERVACOES "
                                 + "FROM OBSERVACOES o "
                                 + "WHERE o.ID_CONTA = "+LabelIdConta.getText()
                                 + " AND '"+datOBS+"' BETWEEN o.DATAI AND o.DATAF");
        DefaultTableModel modelo1 = (DefaultTableModel)TextObs.getModel();
        modelo1.setNumRows(0);
        try
        {
            while(obj_conexao.resultset.next())
            modelo1.addRow(new Object [] {obj_conexao.resultset.getString("OBSERVACOES")});
            obj_conexao.resultset.last();
            }catch(SQLException erro){
                JOptionPane.showMessageDialog(null, erro);
            }
    }