用Myeclipse运行项目报getClassInstance Line: 209 - com/opensymphony/xwork2/spring/SpringObject错

.xwork2.spring.SpringObjectFactoryFile: SpringObjectFactory.javaMethod: getClassInstanceLine: 209 - com/opensymphony/xwork2/spring/SpringObjectFactory.java:209:-1        at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:431)        at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)        at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)        at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.init(FilterInstanceWrapper.java:140)        at com.ibm.ws.webcontainer.filter.WebAppFilterManager._loadFilter(WebAppFilterManager.java:548)        at com.ibm.ws.webcontainer.filter.WebAppFilterManager.loadFilter(WebAppFilterManager.java:462)        at com.ibm.ws.webcontainer.filter.WebAppFilterManager.getFilterInstanceWrapper(WebAppFilterManager.java:319)        at com.ibm.ws.webcontainer.filter.WebAppFilterManager.getFilterChain(WebAppFilterManager.java:379)        at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:860)        at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:932)        at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:500)        at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178)        at com.ibm.wsspi.webcontainer.servlet.GenericServletWrapper.handleRequest(GenericServletWrapper.java:121)        at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.handleRequest(AbstractJSPExtensionServletWrapper.java:239)        at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionProcessor.handleRequest(AbstractJSPExtensionProcessor.java:340)        at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3826)        at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276)        at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931)        at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1583)        at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186)        at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:455)        at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:384)        at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:272)        at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:214)        at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:113)        at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)        at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)        at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)        at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)        at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)        at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)        at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)        at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1550)Caused by: java.lang.NullPointerException        at com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:209)        at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.verifyResultType(XmlConfigurationProvider.java:519)        at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addResultTypes

从svn上down下来公司的某个项目在Myeclipse上运行之后报getClassInstance Line: 209 - com/opensymphony/xwork2/spring/SpringObject错，应为svn上down下来的一般都是正确的版本，我就百度了一下发现网上列举的解决办法

1、Struts的Filter配置 
在web.xml配置文件
       <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>

2、Spring的监听器配置 。

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

3、struts2-spring-plugin-2.1.8.1.jar 是否加入.
        确定已经加入。 

4、Struts的对象工厂是否配置正确 
       在struts.xml中设置struts action托管给spring管理。
       <constant name="struts.objectFactory" value="spring" /> 

但发现都没解决。

我觉把Myeclipse中部署的项目全部清空，再重新部署我需要的项目，运行之后就没报这个错误，不知道是什么原因。先在这边做记录。