How to find servlet API version for glassfish server?

Question

While coding a servlet I found a method that says

Since:
    Servlet 3.1

I guess that if I have the autohint from NetBeans to use it is bec

Answer 1

Look at Java EE version. Servlet (and JSP, JSF, EJB, JPA, etc) version goes hand in hand with Java EE version.

• Java EE 8 = Servlet 4.0
• Java EE 7 = Servlet 3.1
• Java EE 6 = Servlet 3.0
• Java EE 5 = Servlet 2.5
• J2EE 1.4 = Servlet 2.4
• J2EE 1.3 = Servlet 2.3
• J2EE 1.2 = Servlet 2.2

Look at the server homepage/documentation how it presents itself. For GlassFish, that is currently (with 4.1):

World's first Java EE 7 Application Server

So, it's Servlet 3.1.

But, with a big but, that's one thing. The second thing is, the webapp's web.xml version also plays a role. Not everyone knows that.

If your webapp's web.xml is declared conform Servlet 3.1 like below,

then your webapp will also really run in Servlet 3.1 modus.

However, if it's declared conform Servlet 3.0 like below or even older,

then your webapp will run in Servlet 3.0 compatibility modus, even when deployed to a Servlet 3.1 compatible container! The above influences the ServletContext#getMajorVersion() and getMinorVersion(), so they actually say nothing about the container, but only about the webapp itself.

If your webapp's web.xml contains a , regardless of the DTD and the version, then it will run in Servlet 2.3 compatibility modus, even when there's a newer XSD declared!