file:/D:/Tomcat%206.0/webapps/Struts2UserLogin/WEB-INF/classes/struts.xml:3:8

严重: Document is invalid: no grammar found. at (null:3:8)
org.xml.sax.SAXParseException: Document is invalid: no grammar found.
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.Java:195)
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:131)
省略....

 at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
2012-8-17 15:37:11 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter struts2
file:/D:/Tomcat%206.0/webapps/Struts2UserLogin/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:835)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:131)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:100)
省略... 

严重: Exception starting filter struts2
file:/D:/Tomcat%206.0/webapps/Struts2UserLogin/WEB-INF/classes/struts.xml:3:8
 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:123)
 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:830)
 ... 34 more
Caused by: org.xml.sax.SAXParseException: Document is invalid: no grammar found.
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:195)
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:131)

省略...

 at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:121)
 ... 35 more
2012-8-17 15:37:11 org.apache.catalina.core.StandardContext start
严重: Error filterStart
2012-8-17 15:37:11 org.apache.catalina.core.StandardContext start
严重: Context [/Struts2UserLogin] startup failed due to previous errors
2012-8-17 15:37:11 org.apache.coyote.http11.Http11Protocol start
信息: Starting Coyote HTTP/1.1 on http-8080
2012-8-17 15:37:11 org.apache.jk.common.ChannelSocket init
信息: JK: ajp13 listening on /0.0.0.0:8009
2012-8-17 15:37:11 org.apache.jk.server.JkMain start
信息: Jk running ID=0 time=0/30  config=null
2012-8-17 15:37:11 org.apache.catalina.startup.Catalina start
信息: Server startup in 1758 ms

struts.xml配置文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>

    
<struts>
  <!-- 加入默认的struts2配置文件 -->
  <include file="struts-default.xml" />
  <!-- 继承默认的struts2配置文件，概念与Java继承类似 -->
  <package name="default" extends="struts-default" >
    <!-- 此处hello名称是hello.action的url名字 -->
    <action name="hello" class="controller.HelloAction" >
      <!-- success指向配置 -->
      <result name="success">success.html</result>
    </action>
  </package>
</struts>

 因为在struts.xml文件中缺少了DOCTYPT定义，在文件中加入：
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

即可，正确的配置文件如下：

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
    
<struts>
  <!-- 加入默认的struts2配置文件 -->
  <include file="struts-default.xml" />
  <!-- 继承默认的struts2配置文件，概念与Java继承类似 -->
  <package name="default" extends="struts-default" >
    <!-- 此处hello名称是hello.action的url名字 -->
    <action name="hello" class="controller.HelloAction" >
      <!-- success指向配置 -->
      <result name="success">success.html</result>
    </action>
  </package>
</struts>