/usr/share/java/tomcat8-websocket-api.jar is in libtomcat8-java 8.0.14-1+deb8u11.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/tomcat8-websocket-api-8.0.14.jar
/usr/share/java/tomcat8-websocket-api-8.0.14.jar