Is there a Java based Weblogic Client for EngageOne Vault Serviceweb2?

No, there is not a java-based Weblogic client for EngageOne Vault Serviceweb2.  As of this writing (4/2/2020) Serviceweb2 is available for the following platforms:

JBOSS 6
JBOSS 7
JBOSS 9
Tomcat
Websphere

However the source code for Serviceweb2 is also provided as part of the installation, so theoretically a port could be made to work with another application server.
UPDATED:  April 2, 2020