急 jsp高手回答

急急急 在线等jsp高手回答
<%@ page contentType="text/html; charset=gb2312" %>
<%@ page import="bookshop.util.*" %>
<%@ page session="true" %>
<jsp:useBean id="user" scope="page" class="bookshop.run.op_user" />
<%
String mesg = "";
String submit = request.getParameter("Submit");
if (submit!=null && !submit.equals("")) {
if(user.add(request)){
session.setAttribute("username",user.getUserName());
session.setAttribute( "userid", Long.toString( user.getUserid() ) ); 
response.sendRedirect("info.jsp?action=regok");
} else if (!user.getMessage().equals("")) {
mesg = user.getMessage();
} else
mesg = "注册时出现错误，请稍后再试";
}


%>
<script language="javascript">

function openScript(url,name, width, height){
var Win = window.open(url,name,'width=' + width + ',height=' + height + ',resizable=1,scrollbars=yes,menubar=no,status=yes' );
}

function checkform() {
if (document.form1.username.value==""){
alert("用户名不能为空");
document.form1.username.focus();
return false;
}
if (document.form1.passwd.value==""){
alert("用户密码不能为空");
document.form1.passwd.focus();
return false;
}
if (document.form1.passwd.value!=document.form1.passconfirm.value){
alert("确认密码不相符！");
document.form1.passconfirm.focus();
return false;
}

return true;
}

</script>
<%@include file="/bookshop/inc/head.inc"%>
<form name="form1" method="post" action="reg.jsp">
  <%if (!mesg.equals("")) out.println("<p><font color=#ff0000>"+ mesg + "</font></p>");%>
    <table width="450" border="0" cellspacing="1" cellpadding="1" align=center>
 <tr></tr>
      <tr> 
        <td colspan="2" align="center"><b><font color="#0000FF">用户注册</font></b></td>
      </tr>
     <tr></tr>
      <tr> 
        <td width="171" align="right">用户名：</td>
        <td width="272"> 
          <input type="text" name="username" maxlength="20" size="14" >
        </td>
      </tr>
      <tr> 
        <td width="171" align="right">密码：</td>
        <td width="272">
          <input type="password" name="passwd" maxlength="20" size="14">
        </td>
      </tr>
      <tr> 
        <td width="171" align="right">确认密码：</td>
        <td width="272">
          <input type="password" name="passconfirm" maxlength="20" size="14">

        </td>
      </tr>
      <tr> 
        <td width="171" align="right">真实姓名：</td>
        <td width="272">
          <input type="text" name="names" maxlength="20" size="14">
        </td>
      </tr>
      <tr> 
        <td width="171" align="right">性别：</td>
        <td width="272">
          <select name="sex">
            <option>男</option>
            <option>女</option>
          </select>
        </td>
      </tr>
      <tr> 
        <td width="171" align="right">联系地址：</td>
        <td width="272">
          <input type="text" name="address" maxlength="150" size="40">
        </td>
      </tr>
  <tr> 
        <td width="171" align="right">联系邮编：</td>
        <td width="272">
          <input type="text" name="post" maxlength="8" size="8">
        </td>
      </tr>
      <tr> 
        <td width="171" align="right">联系电话：</td>
        <td width="272">
          <input type="text" name="phone" maxlength="25" size="16">
        </td>
      </tr>
      <tr> 
        <td width="171" align="right">电子邮件：</td>
        <td width="272">
          <input type="text" name="email" maxlength="50" size="25">
        </td>
      </tr>
      <tr>
        <td width="171" align="right">&nbsp; </td>
        <td width="272">
          <input type="submit" name="Submit" value="注册" onclick="javascript:return(checkform());">
          <input type="reset" name="reset" value="取消">
        </td>

      </tr>
    </table>  
  </form>
 
<%@include file="/bookshop/inc/tail.inc"%> 


这是它报错的语句
org.apache.jasper.JasperException: An exception occurred processing JSP page /bookshop/reg.jsp at line 9

6: String mesg = "";
7: String submit = request.getParameter("Submit");
8: if (submit!=null && !submit.equals("")) {
9: if(user.add(request)){
10: session.setAttribute("username",user.getUserName());
11: session.setAttribute( "userid", Long.toString( user.getUserid() ) ); 
12: response.sendRedirect("info.jsp?action=regok");


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)



  
[解决办法]
在if(user.add(request))之前先判断你的user对象是否为null！