http://blog.csdn.net/hupanfeng/article/category/1443955
http://limingnihao.iteye.com/blog/781671
http://wenku.baidu.com/link?url=P3lVa2koQekwEKPxEkudso6ZN3l3uA5PgtJyPZmgiLBr9fDqURtXLIUuSu6hnGTuL24N_CclcudBjGqHdrjU8KAf3oweWcaKlTLNMbaCOO_
原文：http://www.cnblogs.com/scott19820130/p/4617521.html