报错信息如下：
15-Sep-2020 18:20:05.418 严重 [http-nio-10086-exec-8] org.apache.catalina.core.ApplicationDispatcher.invoke Servlet.service() for servlet [jsp] threw exception
org.apache.jasper.JasperException: The absolute uri: [http://java.sun.com/jsp/jstl/functions] cannot be resolved in either web.xml or the jar files deployed with this application
at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:55)
at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:293)
at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:80)
15-Sep-2020 18:20:32.108 严重 [http-nio-10086-exec-6] org.apache.catalina.core.ApplicationDispatcher.invoke Servlet.service() for servlet [jsp] threw exception
org.apache.jasper.JasperException: /WEB-INF/jsp/sys/customform/sysCustomFormSettingForm.jsp (line: [6], column: [0]) /commons/customForm.jsp (line: [3], column: [0]) The absolute uri: [http://java.sun.com/jsp/jstl/core] cannot be resolved in either web.xml or the jar files deployed with this application
at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:41)
at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:291)
at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:97)
at org.apache.jasper.compiler.Parser.processIncludeDirective(Parser.java:348)
at org.apache.jasper.compiler.Parser.parseIncludeDirective(Parser.java:381)
at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:484)
之所以报这个错是因为我的一个操作。
我在catalina.properties文件中找到这一行，将后边所有的jar全部删掉，改为了*.jar。
tomcat.util.scan.StandardJarScanFilter.jarsToSkip=*.jar
这种操作后，确实不会再报找不到某个类的错误了，不检测jar包了，系统能够正常启动，能够登陆，但是进入一些页面就会报错。
改为*.jar这个操作视系统架构而定，如果是JSP页面，就不可以修改，如果是前后端分离Vue,html等写的，是可以改的。