一、出現的問題
在使用IntelliJ IDEA 運行JSP頁面時報以下錯誤：
HTTP Status 500 - java.lang.ClassNotFoundException: org.apache.jsp.index_jsp
type Exception report
message java.lang.ClassNotFoundException: org.apache.jsp.index_jsp
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: java.lang.ClassNotFoundException: org.apache.jsp.index_jsp
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:177)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:376)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.lang.ClassNotFoundException: org.apache.jsp.index_jsp
java.net.URLClassLoader$1.run(URLClassLoader.java:366)
java.net.URLClassLoader$1.run(URLClassLoader.java:355)
java.security.AccessController.doPrivileged(Native Method)
java.net.URLClassLoader.findClass(URLClassLoader.java:354)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:132)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:63)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:172)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:376)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.67 logs.
Apache Tomcat/7.0.67
二、問題原因
出現此問題的原因在於我們在jsp頁面中使用了jstl標簽，但是沒有引入jstl相關的jar包。
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
三、解決辦法
引入jstl.jar和standard.jar即可解決。jar包下載鏈接：
https://yunpan.cn/cRQS5UZKg5RNU （提取碼：b33a）