HTTP 状态 500 - 绝对 uri：http://java.sun.com/jsp/jstl/core 无法在 web.xml 或部署的 jar 文件中解析

问题描述

我正在尝试使用 Tomcat 7 在 myEclipse（最新版本）中运行 Web 应用程序。因此，我包含了 JSTL 1.2 jar 文件，如图 here

但是当我运行应用程序并尝试登录（通过登录表单）时，我收到 this 错误。

这是控制台上错误的完整日志：

Jun 20,2021 4:51:11 PM org.apache.catalina.core.Applicationdispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: 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:56)
    at org.apache.jasper.compiler.Errordispatcher.dispatch(Errordispatcher.java:445)
    at org.apache.jasper.compiler.Errordispatcher.jspError(Errordispatcher.java:117)
    at org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:311)
    at org.apache.jasper.compiler.TagLibraryInfoImpl.<init>(TagLibraryInfoImpl.java:152)
    at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
    at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:475)
    at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1427)
    at org.apache.jasper.compiler.Parser.parse(Parser.java:138)
    at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
    at org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
    at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.Applicationdispatcher.invoke(Applicationdispatcher.java:749)
    at org.apache.catalina.core.Applicationdispatcher.processRequest(Applicationdispatcher.java:487)
    at org.apache.catalina.core.Applicationdispatcher.doForward(Applicationdispatcher.java:412)
    at org.apache.catalina.core.Applicationdispatcher.forward(Applicationdispatcher.java:339)
    at edu.securemail.controller.Controller.doPost(Controller.java:177)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
    at java.base/java.lang.Thread.run(Thread.java:832)
Jun 20,2021 4:51:11 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [edu.securemail.controller.Controller] in context with path [/SecureMail] threw exception [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] with root cause
org.apache.jasper.JasperException: 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:56)
    at org.apache.jasper.compiler.Errordispatcher.dispatch(Errordispatcher.java:445)
    at org.apache.jasper.compiler.Errordispatcher.jspError(Errordispatcher.java:117)
    at org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:311)
    at org.apache.jasper.compiler.TagLibraryInfoImpl.<init>(TagLibraryInfoImpl.java:152)
    at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
    at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:475)
    at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1427)
    at org.apache.jasper.compiler.Parser.parse(Parser.java:138)
    at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
    at org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
    at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.Applicationdispatcher.invoke(Applicationdispatcher.java:749)
    at org.apache.catalina.core.Applicationdispatcher.processRequest(Applicationdispatcher.java:487)
    at org.apache.catalina.core.Applicationdispatcher.doForward(Applicationdispatcher.java:412)
    at org.apache.catalina.core.Applicationdispatcher.forward(Applicationdispatcher.java:339)
    at edu.securemail.controller.Controller.doPost(Controller.java:177)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
    at java.base/java.lang.Thread.run(Thread.java:832)

正如我在一些论坛中看到的那样，我还直接将 jstl 文件复制到了项目的 WEB-INF 文件夹中。但错误仍然没有消失。

而且，我的 web.xml 文件如下所示：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>SecureMail</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  
  <servlet>
    <description></description>
    <display-name>Controller</display-name>
    <servlet-name>Controller</servlet-name>
    <servlet-class>edu.securemail.controller.Controller</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>Controller</servlet-name>
    <url-pattern>*.html</url-pattern>
  </servlet-mapping>
  
  <resource-ref>
    <description>DB Connection</description>
    <res-ref-name>jdbc/secure_mail</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
  </resource-ref>
</web-app>

它显示了以下 error。

我不知道它是否与错误有关。我完全糊涂了，我什至不知道从哪里开始。奇怪的是，当我在表单中输入数据时，我的数据库正在更新表，即使 Web 应用程序一直在以我的方式抛出此错误。

解决方法

我明白了！我所要做的就是将 jstl 文件复制到 WEB-INF->lib 文件夹中。问题是，我的项目的 WEB-INF 文件夹中没有 lib 文件夹，所以我创建了一个。之后，我将这三个 jstl 文件复制到 WEB-INF->lib 文件夹和中提琴！我的项目正在运行。