java.lang.NoClassDefFoundError:运行SimpleHelloByEnteringName时的javax/el/ELResolver JSF示例

Question

我是JSF的新手.我正在使用Tomcat 7.0.14并尝试运行SimpleHelloByEnteringName示例但在启动时和运行时遇到以下错误

启动控制台消息:

INFO: Deploying web application directory SimpleHelloByEnteringName
Jun 15, 2011 7:35:42 AM com.sun.faces.config.ConfigureListener contextInitialized
INFO: Initializing Mojarra 2.0.3 (FCS b03) for context '/SimpleHelloByEnteringName'
Jun 15, 2011 7:35:43 AM com.sun.faces.spi.InjectionProviderFactory createInstance
INFO: JSF1048: PostConstruct/PreDestroy annotations present.  ManagedBeans methods marked with these annotations will have said annotations processed.

**Jun 15, 2011 7:35:44 AM com.sun.faces.config.processor.NavigationConfigProcessor addNavigationCasesForRule
WARNING: JSF1058: The resource referred to by to-view-id, 'result.jsp', for navigation from '/pages/inputname.jsp', does not start with '/'.  This will be added for you, but it should be corrected.**

Jun 15, 2011 7:35:44 AM com.sun.faces.config.ConfigureListener$WebConfigResourceMonitor$Monitor <init>
INFO: Monitoring jndi:/localhost/SimpleHelloByEnteringName/WEB-INF/faces-config.xml for modifications
Jun 15, 2011 7:35:44 AM org.apache.coyote.AbstractProtocolHandler start
INFO: Starting ProtocolHandler ["http-apr-8081"]
Jun 15, 2011 7:35:44 AM org.apache.coyote.AbstractProtocolHandler start
INFO: Starting ProtocolHandler ["ajp-apr-8009"]
Jun 15, 2011 7:35:44 AM org.apache.catalina.startup.Catalina start

尝试运行http:// localhost:8081/SimpleHelloByEnteringName /时出现运行时错误

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.lang.NoClassDefFoundError: javax/el/ELResolver
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:342)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

root cause

java.lang.NoClassDefFoundError: javax/el/ELResolver
    java.lang.ClassLoader.defineClass1(Native Method)
    java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
    java.net.URLClassLoader.access$000(URLClassLoader.java:58)
    java.net.URLClassLoader$1.run(URLClassLoader.java:197)
    java.security.AccessController.doPrivileged(Native Method)
    java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    sun.misc.Launcher$ExtClassLoader.findClass(Launcher.java:229)
    java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    java.lang.ClassLoader.loadClass(ClassLoader.java:295)
    sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    java.lang.ClassLoader.loadClass(ClassLoader.java:295)
    java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    org.apache.jasper.runtime.JspFactoryImpl.getJspApplicationContext(JspFactoryImpl.java:220)
    org.apache.jsp.index_jsp._jspInit(index_jsp.java:23)
    org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
    org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:171)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:356)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

root cause

java.lang.ClassNotFoundException: javax.el.ELResolver
    java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    java.security.AccessController.doPrivileged(Native Method)
    java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    sun.misc.Launcher$ExtClassLoader.findClass(Launcher.java:229)
    java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    java.lang.ClassLoader.defineClass1(Native Method)
    java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
    java.net.URLClassLoader.access$000(URLClassLoader.java:58)
    java.net.URLClassLoader$1.run(URLClassLoader.java:197)
    java.security.AccessController.doPrivileged(Native Method)
    java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    sun.misc.Launcher$ExtClassLoader.findClass(Launcher.java:229)
    java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    java.lang.ClassLoader.loadClass(ClassLoader.java:295)
    sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    java.lang.ClassLoader.loadClass(ClassLoader.java:295)
    java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    org.apache.jasper.runtime.JspFactoryImpl.getJspApplicationContext(JspFactoryImpl.java:220)
    org.apache.jsp.index_jsp._jspInit(index_jsp.java:23)
    org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
    org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:171)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:356)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.14 logs.

这个问题是怎么造成的,怎么解决？

Answer 1

警告:JSF1058:to-view-id引用的资源'result.jsp',用于从'/pages/inputname.jsp'导航,不以'/'开头.这将为您添加,但应该更正.

警告与问题无关.JSF已经为你修复了它,但它告诉你应该自己修复它faces-config.xml.

java.lang.ClassNotFoundException:javax.el.E​​LResolver

然而,这非常严重.这可能有几个原因:

• 实际上你根本没有运行Tomcat 7.0,而是缺少这个类的Tomcat 5.5.仔细检查一下.

• 您已经在webapp 或Java的文件夹中删除了一堆servletcontainer特定的库,例如el-api.jar,jsp-api.jar不同的servletcontainer make/version(可能是Tomcat 5.5？)等.可能是为了克服编译问题.移动/复制servletcontainer特定的JAR是错误的解决方案.撤消它并将它们全部删除.WEB-INF/libJRE/lib

• 您web.xml的声明至少不符合Servlet 2.5规范.既然你提到使用Tomcat 7.0,这是一个Servlet 3.0容器,你应该声明web.xml符合Servlet 3.0:

  <?xml version="1.0" encoding="UTF-8"?>
  <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"
      id="WebApp_ID" version="3.0">
  
      <!-- Your config here -->
  </web-app>
  

更新:哦等等...我搜索了"SimpleHelloByEnteringName",我发现这实际上是一个Roseindia.net(颤抖)示例,如下所示:下载和安装"SimpleHelloByEnteringName"JSF示例.我想强调的是,该站点是互联网上最差的 Java EE学习资源.我强烈建议您前往其他资源.

• Coreservlets.com JSF 2.0教程
• Java EE 6教程 - JSF
• Mkyong.com JSF 2.0教程
• 我的Eclipse和Glassfish的JSF 2.0教程