<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="baseurl" value="${pageContext.request.contextPath}/xxxx"></c:set>
此类型的代码。其他页面如果要使用baseurl这个变量，而不想重复在页面中写上如上代码，只需使用页面添入<%@ include file="/WEB-INF/views/include/taglib.jsp"%>该标签代码即可，也就是引入一个jsp文件的内容
。
我模仿试了一下，首先新建一个taglib.jsp，里面放如
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="baseurl" value="${pageContext.request.contextPath}/xxxx"></c:set>代码，然后浏览器输入使用页面的url回车直接报500错误。
我采取了下列方法排除原因
直接在使用的页面写
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="baseurl" value="${pageContext.request.contextPath}/xxxx"></c:set>，去掉<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>引入代码。运行测试时，能正常访问，刷新几次不出错
我尝试把taglib.jsp里面的内容清空（什么都不写），再次运行进入该页面还是直接报500错误。如果去掉<%@ include file="/WEB-INF/views/include/taglib.jsp"%>这句话，在进入页面就没问题，就能正常浏览。
异常代码
message java.lang.ClassNotFoundException: org.apache.jsp.WEB_002dINF.views.modules.sys.user.login_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.WEB_002dINF.views.modules.sys.user.login_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)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1257)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1037)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:980)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
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.WEB_002dINF.views.modules.sys.user.login_jsp
java.net.URLClassLoader.findClass(Unknown Source)
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)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1257)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1037)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:980)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
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/7.0.69 logs.
这个错误，在互联网搜索好像没有相关解决方案，是除了jstl,standard这两个jar包，还需要什么东西吗？
