Tomcat报错！！！！！
at   org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577) at   org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683) at   java.lang.Thread.run(Thread.java:534)Jan   17,   2007   1:14:56   PM   org.apache.struts.action.ActionServlet   initSEVERE:   Unable   to   initialize   Struts   ActionServlet   due   to   an   unexpected   exception   or   error   thrown,   so   marking   the   servlet   as   unavailable.     Most   likely,   this   is   due   to   an   incorrect   or   missing   library   dependency.java.lang.NullPointerException at   org.apache.commons.digester.Digester.getXMLReader(Digester.java:891) at   org.apache.commons.digester.Digester.parse(Digester.java:1572) at   org.apache.struts.action.ActionServlet.parseModuleConfigFile(ActionServlet.java:738) at   org.apache.struts.action.ActionServlet.initModuleConfig(ActionServlet.java:687) at   org.apache.struts.action.ActionServlet.init(ActionServlet.java:333) at   javax.servlet.GenericServlet.init(GenericServlet.java:211) at   org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1029) at   org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:862) at   org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4013) at   org.apache.catalina.core.StandardContext.start(StandardContext.java:4357) at   org.apache.catalina.core.StandardContext.reload(StandardContext.java:3043) at   org.apache.catalina.manager.ManagerServlet.reload(ManagerServlet.java:1014) at   org.apache.catalina.manager.HTMLManagerServlet.reload(HTMLManagerServlet.java:476) at   org.apache.catalina.manager.HTMLManagerServlet.doGet(HTMLManagerServlet.java:98) at   javax.servlet.http.HttpServlet.service(HttpServlet.java:689) at   javax.servlet.http.HttpServlet.service(HttpServlet.java:802) at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237) at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157) at   org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214) at   org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at   org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520) at   org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198) at   org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152) at   org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at   org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540) at   org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102) at   org.apache.catalina.valves.RequestFilterValve.process(RequestFilterValve.java:287) at   org.apache.catalina.valves.RemoteAddrValve.invoke(RemoteAddrValve.java:84) at   org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102) at   org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520) at   org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137) at   org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104) at   org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117) at   org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102) at   org.apache.catalina.core.StandardPipeli