http://www.cnblogs.com/ggjucheng/archive/2013/02/01/2888051.html
http://blog.youkuaiyun.com/desilting/article/details/45505121
http://paddy-w.iteye.com/blog/2081409
http://blog.youkuaiyun.com/scgaliguodong123_/article/details/46993005
http://blog.youkuaiyun.com/cheersu/article/details/8333045