TableColumn column = null;
        Component comp = null;
        int headerWidth = 0;
        int cellWidth = 0;
        Object[] longValues = model.longValues;

        for (int i = 0; i < 5; i++) {
            column = table.getColumnModel().getColumn(i);

            comp = column.getHeaderRenderer().
                             getTableCellRendererComponent(
                                 null, column.getHeaderValue(), 
                                 false, false, 0, 0);
            headerWidth = comp.getPreferredSize().width;

            comp = table.getDefaultRenderer(model.getColumnClass(i)).
                             getTableCellRendererComponent(
                                 table, longValues[i],
                                 false, false, 0, i);
            cellWidth = comp.getPreferredSize().width;  
       }