/usr/share/maven-repo/org/eclipse/jetty/jetty-webapp/9.x/jetty-webapp-9.x.jar is in libjetty9-java 9.2.21-1+deb9u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/maven-repo/org/eclipse/jetty/jetty-webapp/9.x/../../../../../../java/jetty9-webapp.jar