用Struts 2+Hibernate開發. 再次遇到了 Struts 2+JDK 6的衝突問題.
以前在正式環境上發佈系統的時候都是直接將tomcat進程殺掉然後重啓，這樣雖然能夠保證不出問題，但是如果tomcat容器發佈了多個系統就不行，應該這樣會導致其他系統也停止，所以後來就通過tomcat後臺管理來發布, 這樣雖然能發佈上去，但是啓動不了，報如下錯誤：
嚴重: 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:201)
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:3696)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4343)
at org.apache.catalina.core.StandardContext.reload(StandardContext.java:3086)
at org.apache.catalina.manager.ManagerServlet.reload(ManagerServlet.java:912)
at org.apache.catalina.manager.HTMLManagerServlet.reload(HTMLManagerServlet.java:523)
at org.apache.catalina.manager.HTMLManagerServlet.doGet(HTMLManagerServlet.java:113)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:525)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:852)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:584)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1508)
at java.lang.Thread.run(Thread.java:619)
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.<init>(SAX2DOM.java:69)
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)
... 31 more
2008-9-19 0:08:34 org.apache.catalina.core.StandardContext start
第一次啓動能運行, 在http://localhost:8080/manager/html中reload或start就不行.
那基本可斷定是其他jar包有衝突, 應該是XML解析包有衝突.
檢查發佈後的WEB-INF/lib有兩個XML解析包: xml-apis.jar和xerces-2.6.2.jar
這種錯誤真正原因不是JDK 6和Struts 2衝突, 而是 MyEclipse Hibernate 類庫中多了兩個包: xml-apis.jar和xerces-2.6.2.jar, 這兩個包的功能和JDK的衝突了. 解決辦法: 1. 刪除發佈後目錄的 WEB-INF/lib/ 下的這兩個文件; 2. 或者使用JDK 1.5來啓動Tomcat 6.
解決辦法
1>刪除發佈後的目錄下的WEB-INF\lib下的xml-apis.jar和xerces-2.6.2.jar.
2>停止Tomcat,重新啓動就可以，不需要再次發佈