I used Google+ quickstart to be able implement this most of the code was from this example. I implemented obtaining calendar information. I used there javascript as a guide display the page, and use their Servlet examples to fetch calendars

https://developers.google.com/+/quickstart/java

Instructions:

1) go into fullcalendar-sync folder in terminal
2) javac -sourcepath src -d bin -classpath "lib/*" src/com/google/plus/samples/quickstart/Signin.java
3) java -classpath "bin:lib/*" com.google.plus.samples.quickstart.Signin
4) go to your browser and put localhost:4567
5) click on google+ button to authenticate
6) if page hasnt loaded reload the page, you'll see a button that says "Show your calendar in fullcalendar"
7) click "show your calendar in fullcalendar" button
8) fullcalendar rendering of your calendar should be visible from there