Vaadin 7 UI Design By Example Beginner's Guide

User session

A user session is like a place that Java web applications use to store data about each user. Each time a user access the application, a new session object is assigned to it. That means that each user has its own session. A session allows us to identify a user. It is a temporal storage where we (and Vaadin) can put data relevant to a user.

Note

Because sessions are temporal, we can configure their lifetime (or timeout) in web.xml:

<web-app ...>
   ...
  <session-config>
    <session-timeout>20</session-timeout>
  </session-config>
</web-app>

Note

Here, each session will last 20 minutes since the last time the user requested something to the server.

Vaadin automatically preserves the state of UI components (if @preserveOnRefresh is present) by storing ...