public String getJavaVersion() {
      return javaVersion;
    }
Gets the version of Java used to launch and run the GemFire service.

@return a String indicating the version of the Java runtime used in the running GemFire
        service.
@see java.lang.System#getProperty(String) with 'java.verson'
geode-core/src/main/java/org/apache/geode/distributed/AbstractLauncher.java