Note: The following will work for the Oracle JVM – not tested on others. (To get details on non-standard options execute java -X)
You can use the non-standard -XshowSettings flag to show all settings, or alternatively -XshowSettings:properties to show all property settings.
So for example if you execute the following command:
java -XshowSettings:properties -version
This will show you all properties one of which is java.vendor. Not sure if it is possible to get it to output just a single property though.