The superclass “javax.servlet.http.HttpServlet” was not found on the Java Build Path
jsp파일 1번째 라인에서 해당 에러나는 경우.
프로젝트 우클릭 -> Build Path -> Configure Build Path… -> Libraries 탭 -> add library -> server runtime -> was 선택 -> 끝
출처: http://multifrontgarden.tistory.com/52 [우리집앞마당]