Servlets that use container managed transactional entity managers outside of JTA transactions, should close the entity manager after the servlet completes

For any servlet using a container managed entity manager, without a JTA transaction active. The container managed entity manager should be closed after the servlet invocation completes.

One way this might be done, is by dynamically adding the org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve valve, to the JBossWebMetaData metadata object, which is
equivalent to adding the valve to jboss-web.xml.