ClassLoader规格严格

http://lzrzhao.iteye.com/blog/430012

http://jspengxue.iteye.com/blog/40567

http://bigdragon.iteye.com/blog/1635294

http://www.blogjava.net/zhuxing/archive/2008/07/24/217285.html

http://blog.sina.com.cn/s/blog_62be49950100na4f.html

http://blog.sina.com.cn/s/blog_56ae1d58010112td.html