maven-2 - Struts2部署时出错: Unable to load bean: type: class:com. opensymphony.xwork2.ObjectFactory

Question

我正在创建一个基本的 Struts2、Maven webApp，并在部署到 Tomcat 6 或 Jetty 时收到此错误。有人见过这个吗？

  2010-07-29 15:33:38.801::WARN:  failed struts2
    Unable to load bean: type: class:com.opensymphony.xwork2.ObjectFactory - bean - jar:file:/C:/workspaces/test/test/target/work/webapp/WEB-INF/lib/struts2-core-2.1.8.1.jar!/struts-default.xml:29:72
     at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:208)
     at org.apache.struts2.config.StrutsXmlConfigurationProvider.register(StrutsXmlConfigurationProvider.java:101)
     at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:131)
     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.ng.InitOperations.initDispatcher(InitOperations.java:69)
     at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
     at org.mortbay.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97)
     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
     at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:589)
     at org.mortbay.jetty.servlet.Context.startContext(Context.java:139)
     at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220)
     at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:510)
     at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
     at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6PluginWebAppContext.java:110)
     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
     at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
     at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
     at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
     at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
     at org.mortbay.jetty.Server.doStart(Server.java:222)
     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
     at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132)
     at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:357)
     at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:293)
     at org.mortbay.jetty.plugin.Jetty6RunWar.execute(Jetty6RunWar.java:67)
     at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
     at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
     at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:569)
     at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:539)
     at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
     at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
     at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
     at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
     at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
     at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
     at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
     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:592)
     at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
     at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
     at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
     at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
    Caused by: Bean type class com.opensymphony.xwork2.ObjectFactory with the name xwork has already been loaded by bean - jar:file:/C:/workspaces/ulearn/ulearn/target/work/webapp/WEB-INF/lib/struts2-core-2.0.11.2.jar!/struts-default.xml:30:72 - bean - jar:file:/C:/workspaces/ulearn/ulearn/target/work/webapp/WEB-INF/lib/struts2-core-2.1.8.1.jar!/struts-default.xml:29:72
     at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:193)
 ... 47 more

使用 Maven...

  <dependency>
   <groupId>org.apache.struts</groupId>
   <artifactId>struts2-core</artifactId>
   <version>2.1.8.1</version>
  </dependency>

web.xml

 <filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
 </filter>

 <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>

看起来很简单，我不明白为什么它无法加载。我遵循了基本教程。我在 google 上搜索了此错误消息，但找不到任何相关内容。

Answer 1

如果您阅读堆栈跟踪，您的问题实际上非常清楚:

Caused by: Bean type class com.opensymphony.xwork2.ObjectFactory with the 
name xwork has already been loaded by bean -
jar:file:/C:/workspaces/ulearn/ulearn/target/work/webapp/WEB-INF/lib/struts2-core-2.0.11.2.jar!/struts-default.xml:30:72
 - bean -
jar:file:/C:/workspaces/ulearn/ulearn/target/work/webapp/WEB-INF/lib/struts2-core-2.1.8.1.jar!/struts-default.xml:29:72

您拥有 struts2-core-2.0.11.2.jar 的副本 和 struts2-core-2.1.8.1.jar 的副本> 在您的 WEB-INF/lib 目录中。我认为你应该只拥有其中之一。进行一些清理(运行 mvn clean 可能就足够了)。

<小时/>

PS:我不知道为什么你也有来自 C:/workspace/test 的东西，如第一行所示:

jar:file:/C:/workspaces/test/test/target/work/webapp/WEB-INF/lib/struts2-core-2.1.8.1.jar!/struts-default.xml:29:72

你的类路径肯定有一些奇怪和困惑的东西。除了上面给出的解释之外，我没有任何解释。