I built the example in stardog-examples/examples/function as-is, then created a JAR file from the compiled code:
jar tvf mark.jar
0 Tue Mar 16 09:36:52 MST 2021 META-INF/
69 Tue Mar 16 09:36:52 MST 2021 META-INF/MANIFEST.MF
0 Tue Mar 16 09:03:34 MST 2021 META-INF/services/
53 Tue Mar 16 09:36:50 MST 2021 META-INF/services/com.complexible.stardog.plan.filter.functions.TitleCase
0 Tue Mar 16 08:48:24 MST 2021 com/
0 Tue Mar 16 08:48:24 MST 2021 com/complexible/
0 Tue Mar 16 08:48:24 MST 2021 com/complexible/stardog/
0 Tue Mar 16 08:48:24 MST 2021 com/complexible/stardog/examples/
0 Tue Mar 16 08:48:24 MST 2021 com/complexible/stardog/examples/functions/
2933 Tue Mar 16 09:09:12 MST 2021 com/complexible/stardog/examples/functions/TitleCase.class
The file main/resources/META-INF/services/com.complexible.stardog.plan.filter.functions.TitleCase looks like:
com.complexible.stardog.examples.functions.TitleCase
I have placed the resulting JAR in several places: directory pointed to by STARDOG_EXT, in server/dbms/ext, and server/pack. I always get the following error:
Unrecognized function: tag:stardog:api:titleCase
Any help will be appreciated.