Running your first Servlet 4.0 code 

Servlet 4.0 is one the of biggest APIs of Java EE 8. Since the very beginning of the Java EE platform (the old J2EE), the Servlet specification has always played a key role.

The coolest additions of this version are surely HTTP/2.0 and Server Push. Both of them bring performance improvements to your application.

This recipe will use Server Push to do one of the most basic tasks in a web page—loading an image.