今天在升级Hudson从1.343到1.389，更新war包并重启tomcat之后，访问任何页面总是出现以下异常

Dec 28, 2010 9:17:01 AM hudson.ExpressionFactory2$JexlExpression evaluate WARNING: Caught exception evaluating: h.isUnitTest. Reason: java.lang.reflect.InvocationTargetException java.lang.reflect.InvocationTargetException at sun.reflect.GeneratedMethodAccessor124.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.commons.jexl.util.PropertyExecutor.execute(PropertyExecutor.java:125) at org.apache.commons.jexl.util.introspection.UberspectImpl$VelGetterImpl.invoke(UberspectImpl.java:314) at org.apache.commons.jexl.parser.ASTArrayAccess.evaluateExpr(ASTArrayAccess.java:185) at org.apache.commons.jexl.parser.ASTIdentifier.execute(ASTIdentifier.java:75) at org.apache.commons.jexl.parser.ASTReference.execute(ASTReference.java:83) at org.apache.commons.jexl.parser.ASTReference.value(ASTReference.java:57) at org.apache.commons.jexl.parser.ASTReferenceExpression.value(ASTReferenceExpression.java:51) at org.apache.commons.jexl.ExpressionImpl.evaluate(ExpressionImpl.java:80) at hudson.ExpressionFactory2$JexlExpression.evaluate(ExpressionFactory2.java:72) at org.apache.commons.jelly.parser.EscapingExpression.evaluate(EscapingExpression.java:24) at org.apache.commons.jelly.impl.ExpressionScript.run(ExpressionScript.java:66) at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95) at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99) at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95) at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99) at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95) at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:99) at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95) at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105) at org.kohsuke.stapler.jelly.CallTagLibScript.run(CallTagLibScript.java:119) at org.kohsuke.stapler.jelly.CompressTag.doTag(CompressTag.java:44) at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:270) at org.kohsuke.stapler.jelly.JellyViewScript.run(JellyViewScript.java:63) at org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:63) at org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:53) at org.kohsuke.stapler.jelly.JellyFacet$1.dispatch(JellyFacet.java:90) at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:562) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:640) at org.kohsuke.stapler.MetaClass$13.dispatch(MetaClass.java:382) at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:562) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:640) at org.kohsuke.stapler.MetaClass$7.doDispatch(MetaClass.java:242) at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53) at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:562) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:640) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:478) at org.kohsuke.stapler.Stapler.service(Stapler.java:160) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94) at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84) at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:166) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:173) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249) at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:66) at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87) at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76) at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:595) Caused by: java.lang.NoClassDefFoundError: hudson/Main (wrong name: Main) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:620) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124) at java.net.URLClassLoader.defineClass(URLClassLoader.java:260) at java.net.URLClassLoader.access$100(URLClassLoader.java:56) at java.net.URLClassLoader$1.run(URLClassLoader.java:195) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268) at java.lang.ClassLoader.loadClass(ClassLoader.java:251) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1302) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319) at hudson.Functions.getIsUnitTest(Functions.java:1283) ... 81 more

在网上搜了一下都说是升级Hudson不彻底导致，但是按照步骤再试以后还是出现以上异常，步骤如下：
1. shutdown tomcat
2. delete webapps/hudson directory and webapps/hudson.war file
3. copy new hudson.war package to webapps/ directory
4. start tomcat

最后在http://issues.hudson-ci.org/browse/HUDSON-7137找到了解决办法
1. shutdown tomcat
2. delete webapps/hudson/winstone.jar
3. start tomcat

再次访问hudson，一切ok!