为什么一使用<html:form>就提示java.lang.NullPointerException: Module 'null' not found.

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  1.   

    有没有import 语句导入相应的jstl
      

  2.   

    <%@ taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
    是说这句吗?我排除了下,错误可能出现在web.xml里,但具体不知道是什么
      

  3.   

    就设了
    <web-app>
    <servlet>
       <servlet-name>action</servlet-name>
       <servlet-class>org.apache.struts.action.Actionservlet</servlet-class>
       <init-param>
        <param-name>config</param-name>
        <param-value>/WEB-INF/struts-config.xml</param-value>
       </init-param>
    </serlvet>
    <servlet-mapping>
        <servlet-name>action</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    </web-app>
      

  4.   

    没人遇过相同问题? 
    而且我同项目下其他servlet也出错了 (原来运行正常)
    会不会是哪里配置问题还是什么文件坏了.....
      

  5.   

    test.jsp:
    <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
        pageEncoding="ISO-8859-1"%>
    <%@ taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Insert title here</title>
    </head>
    <body>
    <html:form >
    <html:submit property="submit"></html:submit>
    </html:form>
    </body>
    </html>
      

  6.   

    struts-config.xml:
    <?xml version="1.0" encoding="iso-8859-1"?>
    <!DOCTYPE struts-config PUBLIC
            "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"
            "http://struts.apache.org/dtds/struts-config_1_3.dtd">
    <struts-config>
    <form-beans>
    <form-bean name="testBean" type="lineage2BBS.CategoryBean"></form-bean>
    </form-beans>
    <action-mappings>
    <action path="/test" name="testBean" forward="/test.jsp"/>
    </action-mappings>
    </struts-config>
      

  7.   

    访问test.jsp:
     
    exception :org.apache.jasper.JasperException: Module 'null' not found.
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    root cause java.lang.NullPointerException: Module 'null' not found.
    org.apache.struts.taglib.TagUtils.getModuleConfig(TagUtils.java:743)
    org.apache.struts.taglib.TagUtils.getModuleConfig(TagUtils.java:723)
    org.apache.struts.taglib.html.FormTag.lookup(FormTag.java:742)
    org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:417)
    org.apache.jsp.test_jsp._jspx_meth_html_form_0(test_jsp.java:90)
    org.apache.jsp.test_jsp._jspService(test_jsp.java:65)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
      

  8.   

    访问test.do:exception javax.servlet.ServletException: Error instantiating servlet class org.apache.struts.action.ActionServlet
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
    org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
    org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
    org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
    java.lang.Thread.run(Thread.java:595)
    root cause java.lang.NoClassDefFoundError: org/apache/commons/beanutils/Converter
    java.lang.Class.getDeclaredConstructors0(Native Method)
    java.lang.Class.privateGetDeclaredConstructors(Class.java:2328)
    java.lang.Class.getConstructor0(Class.java:2640)
    java.lang.Class.newInstance0(Class.java:321)
    java.lang.Class.newInstance(Class.java:303)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
    org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
    org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
    org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
    java.lang.Thread.run(Thread.java:595)
      

  9.   

    web.xml里加上
    <taglib> 
       <taglib-uri>http://struts.apache.org/tags-html</taglib-uri> 
       <taglib-location>你的STRUTS html标签的tld文件的路径，以/开头</taglib-location> 
    </taglib>
      

  10.   

    我先试试看。我用的是struts1.3.5的 
    从http://struts.apache.org/上下载的struts-examples-1.3.5例子 它的web.xml也没设tld啊啊
    也运行好好的.
    <?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE web-app PUBLIC
            "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
            "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app>
        <display-name>Struts Examples Application</display-name>
        <!-- Standard Action Servlet Configuration (with debugging) -->
        <servlet>
            <servlet-name>action</servlet-name>
            <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>        <!-- Default -->
            <init-param>
                <param-name>config</param-name>
                <param-value>/WEB-INF/struts-config.xml</param-value>
            </init-param>        <!-- Exercise module -->
            <init-param>
                <param-name>config/exercise</param-name>
                <param-value>/WEB-INF/exercise/struts-config.xml</param-value>
            </init-param>        <!-- File Upload module -->
            <init-param>
                <param-name>config/upload</param-name>
                <param-value>/WEB-INF/upload/struts-config.xml</param-value>
            </init-param>        <!-- Validator module -->
            <init-param>
                <param-name>config/validator</param-name>
                <param-value>/WEB-INF/validator/struts-config.xml,
                    /WEB-INF/validator/struts-config-bundles.xml,
                    /WEB-INF/validator/struts-config-i18nVariables.xml,
                    /WEB-INF/validator/struts-config-type.xml,
                    /WEB-INF/validator/struts-config-validwhen.xml
                </param-value>
            </init-param>        <!-- Dispatch Action module -->
            <init-param>
                <param-name>config/dispatch</param-name>
                <param-value>/WEB-INF/dispatch/struts-config.xml</param-value>
            </init-param>        <init-param>
                <param-name>debug</param-name>
                <param-value>2</param-value>
            </init-param>
            <init-param>
                <param-name>detail</param-name>
                <param-value>2</param-value>
            </init-param>
            <load-on-startup>2</load-on-startup>
        </servlet>    <!-- Standard Action Servlet Mapping -->
        <servlet-mapping>
            <servlet-name>action</servlet-name>
            <url-pattern>*.do</url-pattern>
        </servlet-mapping>    <!-- The Usual Welcome File List -->
        <welcome-file-list>
            <welcome-file>index.jsp</welcome-file>
            <welcome-file>index.html</welcome-file>
            <welcome-file>upload.jsp</welcome-file>
        </welcome-file-list></web-app>
      

  11.   

    html:form 标签要求必须有一个ActionForm与页面表单对应，且要配置在struts-config.xml文件中。你试试看。
      

  12.   

    <form-beans>
    <form-bean name="testBean" type="lineage2BBS.CategoryBean"></form-bean>
    </form-beans>
    <action-mappings>
    <action path="/test" name="testBean" forward="/test.jsp"/>
    </action-mappings>
    是这个吧....
    我有写啊
      

  13.   

    那lineage2BBS.CategoryBean中是没有任何属性?
    一定要么表单一致.我只知道这些,希望对你有用。
      

  14.   

    我在struts-examples-1.3.5(http://struts.apache.org载的)项目里这样写就没问题....
    而且FormBean是空的也没事
       怀疑是web.xml或struts-config.xml里哪里有错.经验不足看不出哪儿有错....
    大家帮帮看看吧
       顶者有分哦 .这个问题不解决心不甘啊,总不能我要做什么东西都在struts-examples-1.3.5项目里做吧.作为一个技术问题,大家研究研究吧!!
      

  15.   

    对于访问 test.do 出错：
    root cause java.lang.NoClassDefFoundError: org/apache/commons/beanutils/Converter原因错误说明里已经很清楚了：
    缺少commons-beanutils.jar包
    另外
    检查是否引用所必要的包(可以在你下载的struts源码，实例程序lib目录下找到)至于访问test.jsp页面 出错：应该是会报错的。 我的struts版本 1.2.8，没有指定
    <html:form action=""> 里的 action 就报错，而且
    <html:submit property="submit"></html:submit> 确保你form 里面是否有 submit这个属性