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

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

1、右击web工程-》属性或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。

注意：
按以上方法操作时，若打开Server Runtime后一片空白，需要设置Apache服务器。设置方法为：window->Preferences->Server->Runtime Environment -> add --> 选择Apache的版本后点Next，再填入你apache服务器软件的安装（解压后）地址。