RTIDDSGen Java

I was able to build OpenICE successfully and run the demos which was great! I have a question though, how do types get generated under the RTI data types directory? I noticed that the project depends on a dependency: 

rtiddsgen group: 'com.rti.dds', name: 'rtiddsgen', version: '5.1'

Is that available for newer versions of RTI? Is that in pure java? I guess I could just call the regular generator from a shell command. I like how you can call a main java class though.