项目目录介绍
1. src文件夹：存放作为动态资源文件的java文件
2. web文件夹：存放作为静态资源文件【图片，html，css，js】；存放网站运行时依赖的jar包【mysql驱动】；存放网站核心配置文件【web.xml】
3. WEB-INF:依赖的jar和核心配置文件
4. lib文件夹：是自己手动创建的，默认是没有的，存放依赖的jar
5. web.xml:通知Tomcat当前网站哪些java类是动态资源文件
When nothing seems to help, I go look at a stonecutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred and first blow it will split in two, and I know it was not that blow that did it, but all that had gone before. -- Jacob Riis