In Spring Security 3.0, the contents of the spring-security-core jar were stripped down to the bare minimum. It no longer contains any code related to web-application security, LDAP or namespace configuration. We’ll take a look here at some of the Java types that you’ll find in the core module. They represent the building blocks of the the framework, so if you ever need to go beyond a simple namespace configuration then it’s important that you understand what they are, even if you don’t actually need to interact with them directly.