http://www.cnblogs.com/mengyan/archive/2012/10/09/2716194.html
http://blog.163.com/zqz_20003/blog/static/26945430201062294658703/
http://www.cnblogs.com/mengyan/archive/2012/10/09/2716194.html
http://blog.163.com/zqz_20003/blog/static/26945430201062294658703/