第一个HelloWorld的Struts2程序出错了。请大家看一下是什么问题。感谢。感谢。：（

miaomiaoga

程序在部署后，在TOMCAT里看到的错误是(localhost.2008-12-14.log)：

2008-12-14 19:19:40 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter struts2
Unable to load bean: type: class:com.opensymphony.xwork2.ObjectFactory - bean - jar:file:/D:/Java/tomcat6016/webapps/struts2hello/WEB-INF/lib/struts2-core-2.0.14.jar!/struts-default.xml:30:72
        at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:20
        at org.apache.struts2.config.StrutsXmlConfigurationProvider.register(StrutsXmlConfigurationProvider.java:101)
        at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:131)
        at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:52)
        at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:395)
        at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:452)
        at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:205)
        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:10
        at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3709)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4356)
        at org.apache.catalina.manager.ManagerServlet.start(ManagerServlet.java:1244)
        at org.apache.catalina.manager.HTMLManagerServlet.start(HTMLManagerServlet.java:604)
        at org.apache.catalina.manager.HTMLManagerServlet.doGet(HTMLManagerServlet.java:129)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:525)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:12
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
        at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:856)
        at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:565)
        at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1509)
        at java.lang.Thread.run(Unknown Source)
Caused by: Bean type class com.opensymphony.xwork2.ObjectFactory with the name xwork has already been loaded by bean - jar:file:/D:/Java/tomcat6016/lib/struts2-core-2.0.14.jar!/struts-default.xml:30:72 - bean - jar:file:/D:/Java/tomcat6016/webapps/struts2hello/WEB-INF/lib/struts2-core-2.0.14.jar!/struts-default.xml:30:72
        at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:193)
        ... 29 more





以下是程序代码：
struts2.xml:

<?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>
        <package name="default" extends="struts-default">
                <!-- 在这里添加Action定义 -->
                <action name="HelloWorld" class="example.HelloWorld">
                        <result name="success">/HelloWorld.jsp</result>
                </action>
        </package>
</struts>




HelloWorld.jsp:

<%@ page contentType="text/html; charset=GBK"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
        <head>
                <title>Struts 2 示例</title>
        </head>
        <body>
                <h2>
                        <s:property value="message" />
                </h2>
                ${message}
        </body>
</html>





HelloWorld.java:

package example;

import com.opensymphony.xwork2.ActionSupport;

public class HelloWorld extends ActionSupport {
        public String execute() throws Exception {
                setMessage("你好！Struts 2！";
                return SUCCESS;
        }

        private String message;

        public String getMessage() {
                return message;
        }

        public void setMessage(String message) {
                this.message = message;
        }
}





web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
xmlnssi="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">

<filter>
        <filter-name>struts2</filter-name>
        <filter-class>
        org.apache.struts2.dispatcher.FilterDispatcher
        </filter-class>
</filter>

<filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
</filter-mapping>

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

jilichao

你的jar包冲突，struts2-core-2.0.14.jar和xwork2.jar

miaomiaoga

我看了一下。好像是说我在系统里已经有了另外一个不同版本（或者相同版本）的struts2 core .jar 。

的确是这样。但是我把我原来拷贝到TOMCAT\LIB下的struts2的那些jar删除后。也不行哦。究竟是什么回事呢？

郁闷ing...

miaomiaoga

成功了成功了，我用MYECLIPSE CLEAN了一下。然后再重新部署。再把TOMCAT重起一下。就好了。（访问的文件名还分大小写的哦？）

谢谢。：）