jsp頁面報錯: The superclass "javax.servlet.http.HttpServlet" was not found on the Java；

jsp頁面錯誤如下提示：

問題一：

缺少運作環境，配置java Build Path——>Libraries——> Add Library

選擇MyEclipse Server Library

選擇内置的Tomcat，也可以加入外部Tomcat，依次選擇Finish/Applay确認選擇

問題二：

Multiple annotations found at this line:

    - String cannot be resolved to a type

    - The method getContextPath() from the type HttpServletRequest refers to the missing type 

     String

Multiple annotations found at this line:

    - String cannot be resolved to a type

    - The method getServerName() from the type ServletRequest refers to the missing type 

     String

    - The method getScheme() from the type ServletRequest refers to the missing type 

     String

如圖：

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

選擇JRE System Library 

選擇所需的版本，依次選擇apply确認選項

添加完如圖所示，選擇apply and close完成配置