参考：
http://www.blogjava.net/SpartaYew/archive/2011/05/19/spingsecurity3.html
http://salever.iteye.com/blog/1686425
docs
http://docs.spring.io/spring-security/site/docs/
http://docs.spring.io/spring-security/site/docs/3.2.3.RELEASE/reference/htmlsingle/
http://docs.spring.io/spring-security/site/docs/3.2.4.RELEASE/reference/htmlsingle/
原文：http://my.oschina.net/macleo/blog/315677