javax.servlet.ServletException:java.lang.NoClassDefFoundError:javax/servlet/jsp/jstl/core/ConditionalTagSupport

Question

我使用sitemesh来装饰页面.我正在使用JSP页面.页面工作正常,直到我使用<c:if>条件标签.我在WEB-INF/lib文件夹中有jstl-impl-1.2.jar和sitemesh-3.0-alpha-1.jar文件.我在jsp页面中有以下标记库声明:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql" %>

我正在使用带有java 6的tomcat 7.0.当我在eclipse中创建新的动态Web项目时,我将动态Web模块版本设置为2.4.页面有<c:set/>标签,它们工作正常,但是当我使用if条件标签时,我收到以下错误:

javax.servlet.ServletException: java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/ConditionalTagSupport
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:342)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.sitemesh.webapp.WebAppContext.dispatch(WebAppContext.java:158)
org.sitemesh.webapp.WebAppContext.decorate(WebAppContext.java:133)
org.sitemesh.BaseSiteMeshContext.decorate(BaseSiteMeshContext.java:39)
org.sitemesh.webapp.SiteMeshFilter.postProcess(SiteMeshFilter.java:74)
org.sitemesh.webapp.contentfilter.ContentBufferingFilter.bufferAndPostProcess(ContentBufferingFilter.java:175)
org.sitemesh.webapp.contentfilter.ContentBufferingFilter.doFilter(ContentBufferingFilter.java:126)
org.sitemesh.config.ConfigurableSiteMeshFilter.doFilter(ConfigurableSiteMeshFilter.java:157)

root cause

java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/ConditionalTagSupport
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClassCond(Unknown Source)
java.lang.ClassLoader.defineClass(Unknown Source)
java.security.SecureClassLoader.defineClass(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2820)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1150)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1645)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1523)
org.apache.jasper.compiler.Parser.parseCustomTag(Parser.java:1223)
org.apache.jasper.compiler.Parser.parseElements(Parser.java:1450)
org.apache.jasper.compiler.Parser.parse(Parser.java:138)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:644)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:358)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.sitemesh.webapp.WebAppContext.dispatch(WebAppContext.java:158)
org.sitemesh.webapp.WebAppContext.decorate(WebAppContext.java:133)
org.sitemesh.BaseSiteMeshContext.decorate(BaseSiteMeshContext.java:39)
org.sitemesh.webapp.SiteMeshFilter.postProcess(SiteMeshFilter.java:74)
org.sitemesh.webapp.contentfilter.ContentBufferingFilter.bufferAndPostProcess(ContentBufferingFilter.java:175)
org.sitemesh.webapp.contentfilter.ContentBufferingFilter.doFilter(ContentBufferingFilter.java:126)
org.sitemesh.config.ConfigurableSiteMeshFilter.doFilter(ConfigurableSiteMeshFilter.java:157)

root cause

java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.ConditionalTagSupport
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1678)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1523)
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClassCond(Unknown Source)
java.lang.ClassLoader.defineClass(Unknown Source)
java.security.SecureClassLoader.defineClass(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2820)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1150)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1645)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1523)
org.apache.jasper.compiler.Parser.parseCustomTag(Parser.java:1223)
org.apache.jasper.compiler.Parser.parseElements(Parser.java:1450)
org.apache.jasper.compiler.Parser.parse(Parser.java:138)
org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:644)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:358)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.sitemesh.webapp.WebAppContext.dispatch(WebAppContext.java:158)
org.sitemesh.webapp.WebAppContext.decorate(WebAppContext.java:133)
org.sitemesh.BaseSiteMeshContext.decorate(BaseSiteMeshContext.java:39)
org.sitemesh.webapp.SiteMeshFilter.postProcess(SiteMeshFilter.java:74)
org.sitemesh.webapp.contentfilter.ContentBufferingFilter.bufferAndPostProcess(ContentBufferingFilter.java:175)
org.sitemesh.webapp.contentfilter.ContentBufferingFilter.doFilter(ContentBufferingFilter.java:126)
org.sitemesh.config.ConfigurableSiteMeshFilter.doFilter(ConfigurableSiteMeshFilter.java:157)

Answer 1

此异常表明运行时类路径中缺少JSTL API.你似乎只有JSTL impl.我建议删除它并使用jstl-1.2.jar而不是捆绑了API和impl.

此外,我还建议更新您的web.xml根声明以遵守Servlet 3.0规范.JSTL 1.2至少需要Servlet 2.5,因此对于Servlet 2.4目标项目来说它不能很好地工作.由于Tomcat 7是一个Servlet 3.0容器,而Servlet 3.0提供了2.5以上的许多新酷功能,所以我会选择它.

<web-app 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    version="3.0">

不要忘记相应地修改项目属性中的动态Web项目构面版本.

也可以看看:

• 我们的JSTL维基页面