Using Thread with Vaadin?

Question

I\'m trying to use Thread in my project to send emails. When I click on a Button, a Thread is started and a ProgressBar i

Answer 1

To update UI elements from a background thread, you have to activate either push or polling.

The documentation can be found in the vaadin book.

https://vaadin.com/de/book/vaadin7/-/page/advanced.push.html

In addition to enabling push, you also need to synchronize access to the UI elements as described in section "11.16.3. Accessing UI from Another Thread"