caused By:cannot Locate the chosen objectfactory implementation:spring-[Unknown location]

Today when I was doing the struts and spring framework integration, when I deployed the project to the Tomcat server, the console reported an error:

caused By:unable to load configuration. -[Unknown Location]
At Com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration (configurationmanager.java:70)
At Org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration (dispatcher.java:429)
At Org.apache.struts2.dispatcher.Dispatcher.init (dispatcher.java:471)
... More

caused By:cannot Locate the chosen objectfactory implementation:spring-[Unknown location]

At Org.apache.struts2.config.BeanSelectionProvider.alias (beanselectionprovider.java:391)
At Org.apache.struts2.config.BeanSelectionProvider.alias (beanselectionprovider.java:362)
At Org.apache.struts2.config.BeanSelectionProvider.register (beanselectionprovider.java:288)
At Com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer (defaultconfiguration.java:215)
At Com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration (configurationmanager.java:67)
... More

Of course, the problem is solved in the second hint message:

caused By:cannot Locate the chosen objectfactory implementation:spring-[Unknown location]

The problem occurs because:

Missing Struts2-spring-plugin-2.1.8.1.jar, the file is a jar file that must be used when spring and struts are integrated. The problem is solved by importing the Lib folder.