http://www.cnblogs.com/quanyongan/archive/2013/05/28/3103243.html
http://www.cnblogs.com/xdp-gacl/p/4242221.html
http://blog.csdn.net/subuser/article/details/18988813/
http://jingyan.baidu.com/article/b87fe19e93b8905218356880.html
http://www.cnblogs.com/quanyongan/archive/2013/05/28/3103243.html
原文：http://www.cnblogs.com/longshiyVip/p/5616952.html