Hi Thomas,
The best starting point for java clent is the Quickstart example:
https://github.com/Lightstreamer/Lightstreamer-example-Quickstart-client-java
Furthermore you could slso take a look to the Stocklist example (
https://github.com/Lightstreamer/Lightstreamer-example-StockList-client-java) for a Java Swing version of the Stock-List.
I can confirm that both examples provide a pom.xml file for maven building.
Regards,
Giuseppe