Tomcat中DataSource的配置方法
study 1:
http://tech.ccidnet.com/art/3737/20050118/449743_1.html
study 2:
http://wuhongxian.blog.163.com/blog/static/5096505020079211131896/
study 3: better
http://pengjianbo1.iteye.com/blog/503326
