运行jsp时，报错404

The origin server did not find a current reprsentation for the target resource or is not willing to disclose that one exists.

解决： 
1. web.xml文件位置是否放错，应该放在WebContent/WEB-INF文件夹中 
2. web.xml文件中是否有拼写错误（特别是大小写） 
3. 应该导入的jar包是否正确导入，可存在WebContent/lib文件夹中