[syslog-ng] Question about compiling 3.7.1 on CentOS 7

All; I'm trying to compile 3.7.1 on CentOS 7 with Elasticsearch support which I'm *assuming* requires Java support. However, when I run 'configure', it doesn't enable the Java support. I must be missing a Java dependency somewhere. Does anyone know what dependencies I need for this? Any insight at all would be greatly appreciated. Thanks; John