libservlet3.1-java 1:4.0.1-2~18.04 (s390x binary) in ubuntu bionic

 The Servlet API is the Java platform technology of choice for interacting
 with the web. Servlets provide a component-based, platform-independent
 method, for building web-based applications generating dynamic content.
 Servlets are managed by a container and interact with web clients via a
 request/response paradigm.
 .
 This is a transitional package, the other JavaEE packages should be used
 instead.