Caused by: java.lang.ClassNotFoundException: com.opensymphony.xwork2.util.classloader.ReloadingClassLoader

今天学习到strusts2与spring的整合，把原来可以交给spring产生的东西都扔给了它，终于拜托了繁琐的代码，只专心于逻辑开发就OK了，现在连strusts的action都可以交给spring容器产生了！

在strusts2和spring整合的时候，必不可少的一个jar包就是struts2-spring-plugin.jar，但是需要注意的是，如果jar包的版本冲突也会报异常的，今天本博就遇到了这样一个问题。

Unable to load configuration. - bean - jar:file:/E:/Tomcat6/webapps/struts2_3900_and_Spring/WEB-INF/lib/struts2-spring-plugin-2.1.8.1.jar!/struts-plugin.xml:29:132
a  t com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:58)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:360)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:403)
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:48)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3838)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4488)
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:546)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1041)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:964)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:502)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:321)
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:785)
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:519)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:581)
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:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: Unable to load bean: type:com.opensymphony.xwork2.ObjectFactory class:org.apache.struts2.spring.StrutsSpringObjectFactory - bean - jar:file:/E:/Tomcat6/webapps/struts2_3900_and_Spring/WEB-INF/lib/struts2-spring-plugin-2.1.8.1.jar!/struts-plugin.xml:29:132
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:222)
at org.apache.struts2.config.StrutsXmlConfigurationProvider.register(StrutsXmlConfigurationProvider.java:101)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:165)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55)
... 31 more
Caused by: java.lang.NoClassDefFoundError: com/opensymphony/xwork2/util/classloader/ReloadingClassLoader
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2389)
at java.lang.Class.getDeclaredConstructors(Class.java:1836)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:212)
... 34 more
Caused by: java.lang.ClassNotFoundException: com.opensymphony.xwork2.util.classloader.ReloadingClassLoader
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1516)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1361)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)

　　认真的检查了一遍strusts2需要的jar包：strusts2-core2.1.8.1.jar;struts2-spring-plusin-2.1.8.1.jar;xwork-core-2.1.2.jar;ognl-2.6.11.jar等，发现没有少任何包，那么也许jar包版本不对，或者jar包之间产生冲突，于是就去strusts2.1.8的lib中找，发现xwork的版本太低了，换成2.1.6版本，问题解决！