一个困扰小弟我1个星期的struts返回errors的有关问题

<%@ taglib uri="/WEB-INF/tld/struts-bean.tld" prefix="bean" %><%@ taglib uri="/WEB-INF/tld/struts-html.tld" prefix="html" %><%@ taglib uri="/WEB-INF/tld/struts-logic.tld" prefix="logic" %><html:form action="/logon.do"  ><center><html:errors  /><table border="0" width="100%">  <tr>    <th align="right">      <bean:message key="prompt.username"/>    </th>    <td align="left">      <html:text property="userName" size="15" maxlength="15"/>    </td>  </tr>  <tr>    <th align="right">      <bean:message key="prompt.password"/>    </th>    <td align="left">      <html:password property="password" size="15" maxlength="15"                    redisplay="false"/>    </td>  </tr>  <tr>    <td align="right">    <html:submit property="submit" >                             <bean:message key="button.logon"/>    </html:submit>    </td>    <td align="left">    <html:reset >                             <bean:message key="button.reset"/>    </html:reset>    </td>  </tr></table></center></html:form>

package forms;import javax.servlet.http.HttpServletRequest;import org.apache.struts.action.*;public final class LogonForm extends ActionForm {    private String username = null;    private String password = null;    public String getUserName() {        return (this.username);    }    public void setUserName(String UserName) {        this.username = UserName;    }    public String getPassword() {        return (this.password);    }    public void setPassword(String Password) {        this.password = Password;    }    public void reset(ActionMapping mapping, HttpServletRequest request) {        this.username = null;        this.password = null;    }    public ActionErrors validate(ActionMapping mapping,HttpServletRequest request){                ActionErrors errors  = new ActionErrors();                if((username == null)||(username.length()<1))            errors.add("username",new ActionMessage("hello.no.username.error"));        if((password == null)||(password.length()<1))            errors.add("password",new ActionMessage("hello.no.password.error"));                return errors;    }}

<?xml version="1.0" encoding="utf-8" ?><!DOCTYPE struts-config PUBLIC          "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN"          "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">       <struts-config><!-- ============ Data Source =================================== -->  <!-- ========== Form Bean Definitions =================================== -->  <form-beans>    [b]<form-bean      name="logonForm"                    type="forms.LogonForm"/>[/b]    <form-bean      name="searchForm"                    type="forms.SearchForm"/>                        <form-bean      name="insertForm"                    type="forms.InsertForm"/>     </form-beans>   <!-- ========== Global Forward Definitions ============================== -->  <global-forwards>    <forward   name="logoff"               path="/logoff.do"/>    <forward   name="logon"                path="/logon.jsp"/>    <forward   name="success"              path="/mainMenu.jsp"/>    <forward   name="search"               path="/search.jsp"/>    <forward   name="displayall"           path="/displayall.do"/>    <forward   name="insert"               path="/insert.jsp"/>    <forward   name="mainMenu"             path="/mainMenu.jsp"/>    <forward   name="insertsuccess"              path="/insertsuccess.jsp"/>          </global-forwards>  <!-- ========== Action Mapping Definitions ============================== -->    <action-mappings>   <action    path="/search"              type="actions.SearchAction"              name="searchForm"              scope="request"              input="/search.jsp">      <forward name="success" path="/display.jsp"/>    </action>    <action    path="/displayall"               type="actions.DisplayAllAction"               name="nestedForm"               scope="request"               input="/mainMenu.jsp">      <forward name="success" path="/display.jsp"/>    </action>          <action   path="/insert"              type="actions.InsertAction"              name="insertForm"              scope="request"              input="/insert.jsp"              validate="true">     </action>        <!-- Process a user logoff -->    <action    path="/logoff"               type="actions.LogoffAction">      <forward name="success" path="/index.jsp"/>    </action>    <!-- Process a user logon -->   [b] <action    path="/logon"               type="actions.LogonAction"               name="logonForm"              scope="request"              input="/errors.jsp">      <forward name="success" path="/mainMenu.jsp"/>    </action>[/b]    </action-mappings>   <message-resources parameter="ApplicationResources"/></struts-config>