各位大虾，我在做我的第一个基于struts的简单的系统，出现了问题，大家帮我看看

[NeverFear]

这个系统只是一个用户创建而已，主要文件有 User,Userform,AddUserAction,UserBean,CreateUser.jsp,ViewUser.jsp.

系统是用jbx做的，工程下载地址：
http://www.tokoo.com/kissjava.rar

错误如下，高手帮我解答一下吧！谢谢阿！


Apache Tomcat/4.0.6 - HTTP Status 500 - Internal Server Errortype Exception reportmessage Internal Server Errordescription The server encountered an internal error (Internal Server Error) that prevented it from fulfilling this request.exception javax.servlet.ServletException: Exception creating bean of class kissjava.UserForm: java.lang.ClassCastException
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:471)
at org.apache.jsp.createUser$jsp._jspService(createUser$jsp.java:519)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:107)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:201)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:381)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:473)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:190)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1027)
at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1125)
at java.lang.Thread.run(Thread.java:534)
root cause javax.servlet.jsp.JspException: Exception creating bean of class kissjava.UserForm: java.lang.ClassCastException
at org.apache.struts.taglib.html.FormTag.initFormBean(FormTag.java:547)
at org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:520)
at org.apache.jsp.createUser$jsp._jspService(createUser$jsp.java:288)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:107)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:201)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:381)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:473)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:190)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1027)
at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1125)
at java.lang.Thread.run(Thread.java:534)

[xunyiren]

Exception creating bean of class kissjava.UserForm: java.lang.ClassCastException

[sswt]

ClassCastException

[vampirewp]

Userform.java这个类没有从ActionForm继承

[「已注销」]

谢谢啊！你们真厉害啊！我都看不出来。
顺便请教一下，怎么看java的错误，判断是哪儿出错了呢！那么多错误，我都看不过来了。。。。。。。。。。。。。。

[vampirewp]

Apache Tomcat/4.0.6 - HTTP Status 500 - Internal Server Errortype Exception reportmessage Internal Server Errordescription The server encountered an internal error (Internal Server Error) that prevented it from fulfilling this request.exception javax.servlet.ServletException: Exception creating bean of class kissjava.UserForm: java.lang.ClassCastException
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:471)
at org.apache.jsp.createUser$jsp._jspService(createUser$jsp.java:519)

JSP的异常，很不好看，一般你只要看到这里，大概就知道是错误是发生在哪里，出了什么错误。
最常见的异常有这里出现的类型转换出错(java.lang.ClassCastException)和空指针异常(java.lang.NullPointerException)

[tangbow]

其实经验多了就好了
积累嘛

[「已注销」]

问题又来啦。

Apache Tomcat/4.0.6 - HTTP Status 500 - No action instance for path /createUser could be createdtype Status reportmessage No action instance for path /createUser could be createddescription The server encountered an internal error (No action instance for path /createUser could be created) that prevented it from fulfilling this request.

具体是什么问题呀。看不懂呀！

再次感谢楼上的各位呀！

[sxgz]

struts-config.xml中，有没有配置/createUser 对应的Action