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

新建一个JSP页面时，<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>报错，光标移上去显示：The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path。

上网搜了一下解决办法：

右击web项目，找到Build Path，选择Configure Build Path进入Java Build Path,选择 Libraries-->Add Libraries-->Server Runtime-->next,选择tomcat就OK了。