https://docs.oracle.com/javaee/7/tutorial/webservices-intro.htm
https://docs.oracle.com/javaee/7/tutorial/jaxrs.htm
https://download.oracle.com/otn-pub/jcp/jaxrs-2_1-final-eval-spec/jaxrs-2_1-final-spec.pdf
https://docs.oracle.com/cd/E24329_01/web.1211/e24983/overview.htm#RESTF105
http://www.json.org/
https://docs.oracle.com/javaee/7/tutorial/jaxrs002.htm
https://docs.oracle.com/javaee/7/tutorial/jaxrs-client003.htm
https://www.postman.com/
https://github.com/google/gson/blob/master/UserGuide.md