[에러와 해결] Illegal constant pool type

다음과 같은 오류가 발생

javax.servlet.ServletException: Illegal constant pool type
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:244)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:704)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:590)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:510)
        at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)


원인 : jsp에서 사용하는 class 파일이 손상되었다.

나의 경우에는 FTP로 업로드할 때 전송타입을 잘못해서 생긴 문제였다.