How to set number format for TextField?

Hi everybody!
I have a TextField and I fill it with data using FieldGroup.
The data I set is Double.

I need the textfield display number 4 as “4,00” (2 digits afrer comma).

How can I do this?

I use Vaadin 7.4.2
Please help me!

Use converter with proper format (https://vaadin.com/book/vaadin7/-/page/datamodel.properties.html#datamodel.properties.converter)