If you are new to spring security the below exception might get you confused.
"org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]Offending resource: ServletContext resource"
To resolve this you need to add the below maven dependency to your pom.xml(if your working with maven)
Thats it. Redeploy the app and you are done.