/usr/share/java/plexus-container-default-alpha.jar is in libplexus-container-default-java 1.0-alpha-9-stable-1-7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/plexus-container-default-alpha-1.0-alpha-9-stable-1.jar