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In Vaadin 7.7.0 import versions of package javax.servet was fixed around range [2.5, 3.0.1]. Before that there is no upper bound of version, so Vaadin works perfectly with servlet api 3.1.0. So, last version of Vaadin couldn't be used with Pax Web, a part of Karaf Container, because Pax Web exports only version 3.1.0 of servlet api packages. Maybe it is a good reason to force dependency upgrade of servlet api :) P.S.: javax.servlet-api 3.1.0 available from central maven repo from 26-Apr-2013