http://blog.csdn.net/leo821031/article/details/1545974
http://zhangjunhd.blog.51cto.com/113473/25592/
http://hi.baidu.com/lennydou/item/b57032c0ceb6f5b00c0a7b08
http://www.cnblogs.com/markxue/archive/2012/09/01/2667123.html
http://www.aygfsteel.com/zhaozhenlin1224/archive/2010/02/03/311783.html
http://blog.csdn.net/yhhah/article/details/4158487