问题
Can you point to a class implementing the ServletContainerInitializer interface in the web.xml file or do you have to add a file under the META-INF/services/javax.servlet.ServletContainerInitializer to have a J2EE server pick it up?
If it's possible via the web.xml file, please explain how.
回答1:
I've checked the Java Servlet Specification 3.0 and I've not found any clue that it could be configured via web.xml. I think the only way is the
META-INF/services/javax.servlet.ServletContainerInitializer file.
Please note that the META-INF/services/javax.servlet.ServletContainerInitializer is a file (not a directory) which has to contain the fully qualified name of the initalizer, like:
com.example.MyServletContainerInitializer
It could be inside the war too (tested with Tomcat 7.0.21).
Here is a complete example: http://nullhaus.com/2011/03/using-servlets-3-0-servletcontainerinitializer/
来源：https://stackoverflow.com/questions/7680860/class-implementing-servletcontainerinitializer-in-web-xml