原文連接：http://blog.csdn.net/bebested/article/details/52627890

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Unable to load configuration. - [unknown location]?
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)?
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:970)?
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:438)?
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:482)?
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)?
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)?
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)?
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)?
at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:105)?
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4689)?
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5329)?
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)?
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)?
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)?
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)?
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092)?
at org.apache.catalina.startup.HostConfigDeployDirectory.run(HostConfig.java:1834)atjava.util.concurrent.ExecutorsRunnableAdapter.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.ThreadPoolExecutorWorker.run(ThreadPoolExecutor.java:615)atjava.lang.Thread.run(Thread.java:744)Causedby:Parentpackageisnotdefined:json?default?[unknownlocation]atcom.opensymphony.xwork2.config.providers.XmlConfigurationProvider.buildPackageContext(XmlConfigurationProvider.java:674)atcom.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:523)atcom.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:295)atorg.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:112)atcom.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:264)atcom.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)…21more九月22,20169:12:20下午org.apache.catalina.core.StandardContextfilterStart嚴重:Exceptionstartingfilterstruts2Unabletoloadconfiguration.?[unknownlocation]atorg.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:496)atorg.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)atorg.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)atorg.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)atorg.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)atorg.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:105)atorg.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4689)atorg.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5329)atorg.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)atorg.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)atorg.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)atorg.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)atorg.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092)atorg.apache.catalina.startup.HostConfigDeployDirectory.run(HostConfig.java:1834)?
at java.util.concurrent.ExecutorsRunnableAdapter.call(Executors.java:471)atjava.util.concurrent.FutureTask.run(FutureTask.java:262)atjava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)atjava.util.concurrent.ThreadPoolExecutorWorker.run(ThreadPoolExecutor.java:615)?
at java.lang.Thread.run(Thread.java:744)?
Caused by: Unable to load configuration. - [unknown location]?
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)?
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:970)?
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:438)?
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:482)?
… 18 more?
Caused by: Parent package is not defined: json-default - [unknown location]?
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.buildPackageContext(XmlConfigurationProvider.java:674)?
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:523)?
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:295)?
at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:112)?
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:264)?
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)?
… 21 more

這個錯誤的原因是struts2在package的配置中繼承了json-default?
解決方法是：引入struts2-json-plugin-2.1.8.1.jar