JavaWeb:报错信息The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path

报错原因:javaweb类没有添加tomcat服务器的运行环境

解决方法:

1、右击对应的web project -> Build Path -> Java Build Path -> Libraries -> Add Libray -> Server Runtime -> Tomcat Server
2、切换到Java Build Path界面中的Orader and Export，选择Tomcat。

保存之后秒成功 不用重启