Sorry of it sounds too trivial a question. I maintain a JEE web application running in Tomcat 6.0.29 container. My security team asked me to see if it would be a quick work to upgrade to Tomcat 7 without touching my webappp (or with minimal touching if I have to).
So I thought let's check what JRE version, Servlet spec and JSP spec Tomcat 7 supports in this link - http://tomcat.apache.org/tomcat-7.0-doc/class-loader-howto.html
* First looking into it, I think JRE 5 would be good enough. We are running 5.0.15 version.
* Is the Servlet API version it supports 3.0? Is it the minimal? What if my webapps is written in servlet 2.4?
* Is the JSP API version it supports 2.1? Is it the minimal? What if my webapps is written in JSP 2.0?
And now I wanted to check what my webapp is written in. For that I opened the web.xml file of my app and see the root element has a version attribute that says 2.5. This makes me think our application supports Servlet spec 2.5. Please correct me if I am wrong.
I am not sure how I can check the JSP version. Can you please help me with that?
* Are these version supports forward compatible (a 3.0 servlet container will support servlets written in 2.5 as well or a JSP page written in 2.0 will be working fine in a 2.1 JSP container)?
* Are these version backward compatible otherwise?
* Do I need to update my JRE also for Tomcat 7?
Any guidelines will be appreciated. Thanks in advance.