The usage of Genero Web Services to call a Java service is recommended in a SOA environment. It enables several Genero applications to connect to a centralized Java service without the need to start a new JVM for each running Genero application.

It also provides more flexibility because there is no strong linkage between Genero and the Java virtual machine. You can, for instance, upgrade the Java service without changing anything in your Genero code.

However, due to the XML serialization process and the HTTP transport protocol in Web Services, there can be some performance issues. So if your main concern is performance, it is recommended to use the Genero Java bridge.