问如何将四舍五入的值存储在表中而不只是将其显示为四舍五入

EN

class DoubleEditor4 extends DefaultCellEditor {

    public DoubleEditor4() {
        super(new JFormattedTextField());
    }

    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
        JFormattedTextField editor = (JFormattedTextField) super.getTableCellEditorComponent(table, value, isSelected, row, column);
        if (value!=null){
            String num = (String) value;
            BigDecimal num2 = new BigDecimal(num).setScale(4, BigDecimal.ROUND_HALF_UP);
            String text = num2.toString();
            editor.setHorizontalAlignment(SwingConstants.RIGHT);
            editor.setText(text);
        }
        return editor;
    }   
}

class DoubleRenderer4 extends DefaultTableCellRenderer {
    public DoubleRenderer4() { 
        super();
        this.setHorizontalAlignment(SwingConstants.RIGHT);
    }

    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        value = new BigDecimal(value.toString()).setScale(4, BigDecimal.ROUND_HALF_UP);
        return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column );
    }

    public void setValue(Object value) {
        BigDecimal num2 = new BigDecimal(value.toString()).setScale(4, BigDecimal.ROUND_HALF_UP);
        String text = num2.toString();
        setText(text);
    }
}