http://www.blogjava.net/paulwong/archive/2014/10/29/419177.html
http://www.iteye.com/topic/1125784
http://blog.csdn.net/geloin/article/details/7537425
http://limingnihao.iteye.com/blog/1069503
http://blog.csdn.net/clj198606061111/article/details/20743769
原文：http://www.cnblogs.com/stono/p/4511392.html