Tomcat Realm

參考資料

http://blog.sina.com.cn/s/blog_45c06e6001019rax.html

http://tenderuser.iteye.com/blog/1025990

http://blog.csdn.net/feng88724/article/details/7164983

http://tomcat.apache.org/tomcat-7.0-doc/realm-howto.html