Struts2 报这样的错误，怎么解决？

我在家学习Struts2，按百度经验的方法，在Myeclipse搭建Struts2环境，写了些简单的东西测试一下，启动报这样的错误，怎么解决：You might need to add the following to web.xml:
org.springframework.web.context.ContextLoaderListener
``````````````````````(省略一些东西)严重: Dispatcher initialization failedjava.lang.NullPointerException at com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:220)``````````````````````(省略一些东西)严重: Exception starting filter struts2Class: com.opensymphony.xwork2.spring.SpringObjectFactoryFile: SpringObjectFactory.javaMethod: getClassInstanceLine: 220 - com/opensymphony/xwork2/spring/SpringObjectFactory.java:220:-1``````````````````````(省略一些东西)Caused by: java.lang.NullPointerException at com.opensymphony.xwork2.spring.SpringObjectFactory.getClassInstance(SpringObjectFactory.java:220)``````````````````````(省略一些东西)严重: Exception starting filter struts2java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter我怀疑是包冲突造成的。我没添加其他东西啊，直接按照百度经验搭建 的Struts2环境。请帮助解决，十分感激！

没有看到你的包：
处理方法：
核对lib包 如下：
commons-fileupload-1.2.1.jar，
commons-io-1.3.2.jar
commons-logging-1.0.4.jar
freemarker-2.3.16.jar
ognl-3.0.jar
struts2-core-2.2.1.jar
xwork-core-2.2.1.jar

包好多，但删不掉啊，怎么删？

右边的删除键是灰色的。这是myeclipse 自带的不包，我按百度经验步骤搭的Struts2环境。

以下是搭建的连接：http://jingyan.baidu.com/article/ed2a5d1f3353d709f6be17a6.html