my requirement is :
open a firefox, input the url then new one application instance, and many windows in it.
do some operation to generate some components
open a IE6, input the same url
you will find that some components you created in firefox occurs in IE,
this is caused by sync?
so how to create multiple application instance in vaadin?
or modify some config files?
Vaadin creates a separate instance of the Application class for each session. You shouldn’t be able to access the same Application instance in IE and Firefox.
My guess is that you have used some static variables in your code. That of course leads to those values to be shared among all Application instances.