问题
I'm trying to build a JavaServer Faces 2.0 project (using Apache Myfaces 2.0.2 + Tomcat 7.0.25 via Eclipse Indigo). All seems to be set, Tomcat starts ok, but when I try to open a web page I get the error:
SEVERE: An exception occurred javax.faces.FacesException: java.lang.NoClassDefFoundError: com/sun/facelets/tag/jsf/ComponentHandler
As I understand, some jar(s) are missing, the one which has this class: com.sun.facelets.tag.jsf.ComponentHandler.
Jar finder tells me that I should have "jsf-facelets.jar" (http://www.jarfinder.com/index.php/java/info/com.sun.facelets.tag.jsf.ComponentHandler/).
However, there is no download section at http://facelets.java.net/.
Which jars do I need? Why isn't MyFaces enough?
INFO: Server startup in 20457 ms
10.02.2012. 15:51:03 org.apache.myfaces.renderkit.ErrorPageWriter handleThrowable
SEVERE: An exception occurred
javax.faces.FacesException: java.lang.NoClassDefFoundError: com/sun/facelets/tag/jsf/ComponentHandler
at org.apache.myfaces.shared_impl.context.ExceptionHandlerImpl.wrap(ExceptionHandlerImpl.java:241)
at org.apache.myfaces.shared_impl.context.ExceptionHandlerImpl.handle(ExceptionHandlerImpl.java:156)
at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:191)
at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1805)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: com/sun/facelets/tag/jsf/ComponentHandler
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2836)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1160)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1668)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1546)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.apache.myfaces.shared_impl.util.ClassUtils.classForName(ClassUtils.java:178)
at org.apache.myfaces.view.facelets.util.ReflectionUtil.forName(ReflectionUtil.java:67)
at org.apache.myfaces.view.facelets.compiler.TagLibraryConfig$LibraryHandler.createClass(TagLibraryConfig.java:475)
at org.apache.myfaces.view.facelets.compiler.TagLibraryConfig$LibraryHandler.endElement(TagLibraryConfig.java:373)
at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
at org.apache.xerces.impl.dtd.XMLNSDTDValidator.endNamespaceScope(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.handleEndElement(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.endElement(Unknown Source)
at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanEndElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl.parse(Unknown Source)
at javax.xml.parsers.SAXParser.parse(Unknown Source)
at org.apache.myfaces.view.facelets.compiler.TagLibraryConfig.create(TagLibraryConfig.java:632)
at org.apache.myfaces.view.facelets.compiler.TagLibraryConfig.loadImplicit(TagLibraryConfig.java:670)
at org.apache.myfaces.view.facelets.compiler.Compiler.initialize(Compiler.java:93)
at org.apache.myfaces.view.facelets.compiler.Compiler.compileViewMetadata(Compiler.java:125)
at org.apache.myfaces.view.facelets.impl.DefaultFaceletFactory._createViewMetadataFacelet(DefaultFaceletFactory.java:311)
at org.apache.myfaces.view.facelets.impl.DefaultFaceletFactory.getViewMetadataFacelet(DefaultFaceletFactory.java:394)
at org.apache.myfaces.view.facelets.impl.DefaultFaceletFactory.getViewMetadataFacelet(DefaultFaceletFactory.java:376)
at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage._getViewMetadataFacelet(FaceletViewDeclarationLanguage.java:1902)
at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage.access$000(FaceletViewDeclarationLanguage.java:128)
at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage$FaceletViewMetadata.createMetadataView(FaceletViewDeclarationLanguage.java:2136)
at org.apache.myfaces.lifecycle.RestoreViewExecutor.execute(RestoreViewExecutor.java:161)
at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:171)
... 18 more
Caused by: java.lang.ClassNotFoundException: com.sun.facelets.tag.jsf.ComponentHandler
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1701)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1546)
... 58 more
回答1:
Relevant part from the stacktrace:
Caused by: java.lang.NoClassDefFoundError: com/sun/facelets/tag/jsf/ComponentHandler
...
at org.apache.myfaces.view.facelets.compiler.TagLibraryConfig$LibraryHandler.createClass(TagLibraryConfig.java:475)
at org.apache.myfaces.view.facelets.compiler.TagLibraryConfig$LibraryHandler.endElement(TagLibraryConfig.java:373)
There's somewhere a Facelets 1.x tag library in your webapp and I think it's a custom one as you don't seem to be using JSF 1.x targeted component libraries (such as RichFaces 3.x or Tomahawk for JSF 1.x). Look for *.taglib.xml files in your webapp (they're usually in /WEB-INF or /META-INF) and update its XML root declaration to comply Facelets 2.0 as follows:
<facelet-taglib
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-facelettaglibrary_2_0.xsd"
version="2.0">
See also:
- Migrating from JSF 1.2 to JSF 2.0
回答2:
Ok, the problem was that I was using Tomahawk for JSF 1.2 instead of Tomahawk for JSF 2.0 while I was using JSF 2.0.
来源：https://stackoverflow.com/questions/9228935/which-jars-do-i-need-in-order-to-avoid-noclassdeffounderror-com-sun-facelets-t