错误信息：
严重: Exception starting filter struts2Unable to load configuration. - action - file:/C:/Users/Xiejdm/Workspaces/MyEclipse%20Professional%202014/.metadata/.me_tcat7/webapps/0719StrutsCRUD/WEB-INF/classes/struts.xml:24:86 at 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.initFilter(ApplicationFilterConfig.java:277) at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:258) at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:382) at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:103) at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4650) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5306) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:618) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1100) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1618) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:744)Caused by: Error building results for action userinfo in namespace /UserEntity - action - file:/C:/Users/Xiejdm/Workspaces/MyEclipse%20Professional%202014/.metadata/.me_tcat7/webapps/0719StrutsCRUD/WEB-INF/classes/struts.xml:24:86 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addAction(XmlConfigurationProvider.java:366) at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:460) at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:265) at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:111) at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:189) at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55) ... 21 moreCaused by: There is no result type defined for type 'json' mapped with name 'success'. Did you mean 'json'? - result - file:/C:/Users/Xiejdm/Workspaces/MyEclipse%20Professional%202014/.metadata/.me_tcat7/webapps/0719StrutsCRUD/WEB-INF/classes/struts.xml:25:24 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.buildResults(XmlConfigurationProvider.java:613) at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addAction(XmlConfigurationProvider.java:364) ... 26 more
解决方案：我的情况是缺少struts2-json-plugin-2.3.16.3.jar包。还有要注意的地方是extends="json-default,hibernate-default"，而不是extends="struts-default".