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

错误原因：The superclass “javax.servlet.http.HttpServlet” was not found on the Java Build Path
错误分析：没有将tomacat加入
解决步骤：1.单击文件右键，构建路径

2，点击add library——》server runtime——》单击tomcat，然后应用即可解决