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Deploying Vaadin Application using Maven and Jetty

Jesus Martinez
1 decade ago Aug 31, 2010 7:30pm
Jean-François Lamy
1 decade ago Aug 31, 2010 8:32pm

The singleton is shared accross all sessions of your Web Application, because it was most likely created as a static and loaded by the class loader dedicated to your Web Application

That is one cause of unwanted sharing, but not the only one: servlet containers instantiate each servlet once, and call the service() method once per HTTP request. So if you have
1) a regular variable in a servlet class, or
2) any type of static variable (including a typical singleton), or
3) anything in the application context, or
4) anything in the JNDI context,

ALL of those are shared.

A singleton should only be used for something that MUST be shared across all browsers and sessions. You want exactly the opposite. Anything private to each browser should be a private variable inside the Vaadin Application (which is the HTTP Session).

Jesus Martinez
1 decade ago Sep 03, 2010 9:29pm
Jean-François Lamy
1 decade ago Sep 04, 2010 1:36am

Tomcat will be the same as Jetty.

If for whatever reason a container handles servlets differently, creating new instances, I would strongly advise against relying on the behaviour. The behaviour I described is pretty much universal AFAIK.

Jesus Martinez
1 decade ago Sep 07, 2010 7:44pm