As discovered via Logstash : logstash-plugins/logstash-patterns-core#237

It appears that the Ingest Grok processor also has duplicated JAVACLASS and JAVAFILE definitions

https://github.com/elastic/elasticsearch/blob/6.5/libs/grok/src/main/resources/patterns/java

We should keep the top ones

JAVACLASS (?:[a-zA-Z$_][a-zA-Z$_0-9]*\.)*[a-zA-Z$_][a-zA-Z$_0-9]*
JAVAFILE (?:[A-Za-z0-9_. -]+)

and remove the lower ones.