参考资料:
http://blog.youkuaiyun.com/lylwo317/article/details/52163304
http://www.cnblogs.com/xiaoluo501395377/p/3383130.html
http://www.cnblogs.com/flyoung
2008/archive/2013/08/11/3251148.html
http://blog.youkuaiyun.com/heyutao007/article/details/49738887