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

maven構建的web工程（war打包）,新建jsp文件是出現叉叉，錯誤提示爲The superclass javax.servlet.http.HttpServlet was not found on the Java Build Path   。解決辦法就是：右鍵點擊錯誤的（上面有叉叉）的web工程，而後Build Path ，Configure Build Path ，Libraies，add Libray ，選擇server running time 而後next，finish。