Fatal error setting up Struts-Spring Integration from xwork-core-2.2.1.jar

I am configuring Struts2 and Hibernate frameworks, and I am getting an error from xwork-core-2.2.1.jar:

9:08:22,406  INFO StrutsSpringObjectFactory:42 - Initializing Struts-Spring integration...
19:08:22,421 FATAL StrutsSpringObjectFactory:89 - ********** FATAL ERROR STARTING UP STRUTS-SPRING INTEGRATION **********
Looks like the Spring listener was not configured for your web app! 
Nothing will work until WebApplicationContextUtils returns a valid ApplicationContext.
You might need to add the following to web.xml: 
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
19:08:22,453 DEBUG XmlConfigurationProvider:68 - Loaded [BUILDER] {PackageConfig Name:struts-default namespace: parents:[]}
19:08:22,468 ERROR Dispatcher:38 - Dispatcher initialization failed
java.lang.NullPointerException
    at com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:220)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.verifyResultType(XmlConfigurationProvider.java:530)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addResultTypes(XmlConfigurationProvider.java:501)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:457)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:275)
    at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfiguratio开发者_运维知识库nProvider.java:111)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:204)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:371)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:415)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
    at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3693)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4340)
    at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1105)
    at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1203)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:293)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
    at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1337)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1601)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1610)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1590)
    at java.lang.Thread.run(Unknown Source)
Dec 8, 2010 7:08:22 PM org.apache.catalina.core.StandardContext filterStart
SEVERE: Exception starting filter sample-filter
Class: com.opensymphony.xwork2.spring.SpringObjectFactory
File: SpringObjectFactory.java
Method: getClassInstance
Line: 220 - com/opensymphony/xwork2/spring/SpringObjectFactory.java:220:-1
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:428)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
    at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3693)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4340)
    at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1105)
    at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1203)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:293)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
    at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1337)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1601)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1610)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1590)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:220)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.verifyResultType(XmlConfigurationProvider.java:530)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addResultTypes(XmlConfigurationProvider.java:501)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:457)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:275)
    at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:111)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:204)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:371)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:415)
    ... 16 more
Dec 8, 2010 7:08:22 PM org.apache.catalina.core.StandardContext start
SEVERE: Error filterStart
Dec 8, 2010 7:08:22 PM org.apache.catalina.core.StandardContext start
SEVERE: Context [/hiber] startup failed due to previous errors

My WEB.XML is:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>

 <filter>
  <filter-name>sample-filter</filter-name>
  <filter-class>
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
  </filter-class>
  </filter>

  <filter-mapping>
    <filter-name>sample-filter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>


</web-app>

I don't know what the problem is and I don't want to have to configure Spring. What should I do?

is the struts2-spring-plugin on your classpath? If so, you should remove it. Also, what's the value of struts.objectFactory? It will be set in either struts.xml or struts.properties. If it's "spring", then that's why Spring is being used. If not, just remove the struts2-spring-plugin jar.

Problem is that you have configured spring-plugin in your application as well as you have pointed spring as your default dependency injection container but same time if you want to use spring with struts2 you also have to register the ApplicationContext Lister of spring.

either register the Listner in the web.xml file or as suggested just remove the entry from the struts.property or struts config file

<constant name="struts.objectFactory" value="spring" />
struts.objectFactory = org.apache.struts2.spring.StrutsSpringObjectFactory

or need to add the following in the web.xml

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

Choice is all your if you want to use Spring with struts2 or not