http://blog.chinaunix.net/uid-8996530-id-3195808.html
http://www.cnblogs.com/HondaHsu/p/4885318.html
http://www.bitscn.com/pdb/oracle/200604/17839.html
http://www.cnblogs.com/kerrycode/p/3254154.html
原文：http://www.cnblogs.com/diyunpeng/p/6518241.html