求大牛解答关于Struts2的<s:debug>标签的问题

很奇怪，不加<s:debug>标签在JSP文件里可以顺利执行没什么错误，可是只要一加这个标签就报错：
错误如下Struts Problem Report
Struts has detected an unhandled exception: Messages: Exception in JSP: /showUsers.jsp:33 30: 31: 32: 33: 34: 35: 36: Stacktrace: 
 
File: org/apache/jasper/servlet/JspServletWrapper.java 
Line number: 451 
--------------------------------------------------------------------------------Stacktraces
org.apache.jasper.JasperException: Exception in JSP: /showUsers.jsp:33 30: 31: 32: 33: 34: 35: 36: Stacktrace: 
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:451)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:321)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:257)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:659)
    org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:457)
    org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:395)
    org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:311)
    org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:154)
    org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
    com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:361)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:265)
    com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468)
    org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:837)
    org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:640)
    org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1287)
    java.lang.Thread.run(Thread.java:619)
    --------------------------------------------------------------------------------You are seeing this page because development mode is enabled. Development mode, or devMode, enables extra debugging behaviors and reports to assist developers. To disable this mode, set:   struts.devMode=falsein your WEB-INF/classes/struts.properties file. 百度GOOGLE都查了也找不到答案，求大神求解答，万分感谢

解决方案 »

  1.   

    showUsers.jsp:33这一行（33行）都有些什么啦。
    你另外写一个空的JSP文件试过没有？
      

  2.   

    ShowUsers.jsp如下：
    <%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
    <%@ taglib uri="/struts-tags" prefix="s" %><%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'showUser.jsp' starting page</title>
        
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->  </head>
      
      <body>
        <s:iterator value="users">
        
          <s:property value="username"/> 
          
        </s:iterator>
    <s:debug></s:debug>
       
      </body>
    </html>就是那个<s:debug></s:debug>如果不加上运行很成功，能显示出遍历的数组List<User> users内容来，可是加上<s:debug></s:debug>页面就报错，囧死了