tomcat页面直接报404错误，直接重启tomcat后访问页面继续是404错误，启动的过程中仍然报错，信息如下：
严重: Exception starting filter struts2
Caught exception while loading file struts-default.xml - [unknown location]
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:839)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:131)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:100)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:130)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:52)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:395)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:452)
at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:205)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3800)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4450)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:526)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:987)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:909)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:495)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1206)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:314)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:722)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:583)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: java.lang.ClassCastException: org.apache.xerces.parsers.XML11Configuration cannot be cast to org.apache.xerces.xni.parser.XMLParserConfiguration
at org.apache.xerces.parsers.DOMParser.<init>(Unknown Source)
at org.apache.xerces.parsers.DOMParser.<init>(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.<init>(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderFactoryImpl.newDocumentBuilder(Unknown Source)
at com.sun.org.apache.xalan.internal.xsltc.trax.SAX2DOM.createDocument(SAX2DOM.java:326)
at com.sun.org.apache.xalan.internal.xsltc.trax.SAX2DOM.<init>(SAX2DOM.java:85)
at com.sun.org.apache.xalan.internal.xsltc.runtime.output.TransletOutputHandlerFactory.getSerializationHandler(TransletOutputHandlerFactory.java:187)
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.getOutputHandler(TransformerImpl.java:392)
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerHandlerImpl.setResult(TransformerHandlerImpl.java:137)
at com.opensymphony.xwork2.util.DomHelper$DOMBuilder.setup(DomHelper.java:213)
at com.opensymphony.xwork2.util.DomHelper$DOMBuilder.<init>(DomHelper.java:198)
at com.opensymphony.xwork2.util.DomHelper$DOMBuilder.<init>(DomHelper.java:189)
at com.opensymphony.xwork2.util.DomHelper$DOMBuilder.<init>(DomHelper.java:175)
at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:115)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:830)
... 34 more
2012-3-16 9:41:18 org.apache.catalina.core.StandardContext start
严重: Error filterStart
2012-3-16 9:41:18 org.apache.catalina.core.StandardContext start
严重: Context [/service] startup failed due to previous errors
2012-3-16 9:41:18 org.apache.catalina.core.ApplicationContext log
信息: Closing Spring root WebApplicationContext
2012-3-16 9:41:18 org.apache.coyote.http11.Http11Protocol start
信息: Starting Coyote HTTP/1.1 on http-80
2012-3-16 9:41:19 org.apache.jk.common.ChannelSocket init
信息: JK: ajp13 listening on /0.0.0.0:8009
2012-3-16 9:41:19 org.apache.jk.server.JkMain start
信息: Jk running ID=0 time=0/24 config=null
2012-3-16 9:41:19 org.apache.catalina.startup.Catalina start
信息: Server startup in 35855 ms
网上查资料说是jar包有冲突, 应该是XML解析包有冲突. 检查发布后的WEB-INF/lib有两个XML解析包: xml-apis.jar和xerces-2.6.2.jar 这种错误真正原因不是JDK 6和Struts 2冲突, 而是 MyEclipse Hibernate 类库中多了两个包: xml-apis.jar和xerces-2.6.2.jar, 这两个包的功能和JDK的冲突了.
解决办法:
1. 将发布后目录的WEB-INF/lib/下的xml-apis.jar和xerces-2.6.2.jar这两个的这两个文件重命名一下即可！（这是我尝试的是方法）
2. 我的tomcat是1.6版本，或者使用JDK 1.5来启动Tomcat 6.（未尝试）