struts 2.0非常奇怪的问题，大家帮我分析分析


为什么我一用到这个标签就出错s:property value="message"/>源码：<%@ page contentType="text/html; charset=UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
    <title>Sign On</title>
</head><body>
<s:property value="message"/>
 <form name="classForm" method="post" action="NewCategory.page">
          <table width="90%" border="0" cellspacing="1" cellpadding="1">
            <tr> 
              <td align="right" width="35%">图书分类名称：</td>
              <td width="65%"> 
                <input type="text" name="categoryName" maxlength="40" size="30">
              </td>
            </tr>            
            <tr> 
              <td align="right" width="35%">&nbsp;</td>
              <td width="65%"> 
                <input type="submit" name="Submit" value="提交">
                <input type="reset" name="reset" value="重置">
              </td>
            </tr>
          </table>
        </form>
</body>
</html>错误信息如下HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /manage/AddCategory.jsp at line 96: </head>
7: 
8: <body>
9: <s:property value="message"/>
10:  <form name="classForm" method="post" action="NewCategory.page">
11:           <table width="90%" border="0" cellspacing="1" cellpadding="1">
12:             <tr> 
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:515)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:426)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause java.lang.NullPointerException
org.apache.struts2.views.jsp.TagUtils.getStack(TagUtils.java:58)
org.apache.struts2.views.jsp.StrutsBodyTagSupport.getStack(StrutsBodyTagSupport.java:54)
org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:49)
org.apache.jsp.manage.AddCategory_jsp._jspx_meth_s_005fproperty_005f0(AddCategory_jsp.java:109)
org.apache.jsp.manage.AddCategory_jsp._jspService(AddCategory_jsp.java:65)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:384)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.10 logs.
--------------------------------------------------------------------------------Apache Tomcat/6.0.10

解决方案 »

  1.   


    是这个标签<s:property value="message"/>
      

  2.   

    java.lang.NullPointerExceptionnull值查找下吧
      

  3.   


    s:property value="message"/>这个是我复制的时候弄错了，源因不是这
      

  4.   

    把<%@ taglib prefix="s" uri="/struts-tags" %>改成
    <%@ taglib prefix="s" uri="/WEB-INF/struts-tags.tld" %>,然后把web.xml里的声明删掉试试！
      

  5.   

    <%-- 
        Document   : index
        Created on : 2008-9-5, 23:09:10
        Author     : Administrator
    --%><%@page contentType="text/html" pageEncoding="UTF-8"%>
    <%@ taglib prefix="s" uri="/struts-tags" %>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
       "http://www.w3.org/TR/html4/loose.dtd"><html>
        <head>
            <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
            <title>JSP Page</title>
        </head>
        <body>        <s:form action="login">
                <s:textfield name="username" label="username" ></s:textfield>
                <s:password name="password" label="password" ></s:password>
                <s:submit label="submit" />
            </s:form>
        </body>
    </html>