问题:

Can you tell me how to know which servlet and JSP version am I using ? I use NetBeans IDE 7.1.2 for creating Servlets and JSP.

回答1:

You can get the details programatically using ServletContext #getMajorVersion() and #getMinorVersion().

For knowing the JSP version corresponding to the Servlet, you can get details from this Tomcat page

Below is the summary,

Servlet 2.5 uses JSP 2.1 
Servlet 2.4 uses JSP 2.0 
Servlet 2.3 uses JSP 1.2 
Servlet 2.2 uses JSP 1.1 
Servlet 2.1 uses JSP 1.0

回答2:

You can easily check the JSP,SERVER and SERVLET version. Add the following code in your jsp page after that run using any IDE Tools.

Server Version: <%= application.getServerInfo() %><br>
Servlet Version: <%= application.getMajorVersion() %>.<%= application.getMinorVersion() %>
JSP Version: <%= JspFactory.getDefaultFactory().getEngineInfo().getSpecificationVersion() %> <br>

回答3:

The version is declared in the web.xml file using the attribute version.

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
     version="2.5">
...
</web-app>