JSP连接数据库的问题刚刚学不知道错误怎么改望高手教我

此程序建立在系统DSN数据源是usergl数据表是user.mdb的数据基础上的
不知道为什么就是有异常  试了好久没找出原因望高手告诉我啊
报错如下：
HTTP Status 500 -

--------------------------------------------------------------------------------

type Exception report

message

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 /zhuce2.jsp at line 52

49:    username=request.getParameter("txtname");
50:    usersex=request.getParameter("radsex");
51:    userwork=request.getParameter("selwork");
52:    n=userid.length()*userid2.length()*password.length()*password2.length()*useremail.length()*username.length();
53:    %>
54:  <%
55:  if(n!=0&password.equals(password2))

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:524)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:435)
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.jsp.zhuce2_jsp._jspService(zhuce2_jsp.java:111)
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:393)
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/6.0.13 logs.

--------------------------------------------------------------------------------
pache Tomcat/6.0.13
JSP程序如下：
<%@ page language="java"  import="java.sql.*" pageEncoding="gb2312"%>
<%
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>注册窗口</title>
    <meta http-equiv="content-type" content="text/html; charset=gb2312">
<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">


  </head>
   <body bgcolor="#ccccffffff">
<div align="center">
<p>
<font size="5" face="隶书">
<b>
<font color="#cc00cc">
注册窗口
</font></b></font></p>
<hr>
<%String userid=new String();
  String userid2=new String();
  String password=new String();
  String password2=new String();
  String useremail=new String();
  String username=new String();
  String usersex=new String();
  String userwork=new String();
  String temp=new String();
  int n;
  %>
<% userid=request.getParameter("txtuserid");
   userid2=request.getParameter("txtuserid2");
   password=request.getParameter("txtpassword");
   password2=request.getParameter("txtpassword2");
   useremail=request.getParameter("txtemail");
   username=request.getParameter("txtname");
   usersex=request.getParameter("radsex");
   userwork=request.getParameter("selwork");
   n=userid.length()*userid2.length()*password.length()*password2.length()*useremail.length()*username.length();
   %>
<%
if(n!=0&password.equals(password2))
{
try
    {
String url=new String();
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
url = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=D:/myeclipse/JJ/WebRoot/user.mdb";
Connection con=DriverManager.getConnection(url);
Statement stmt=con.createStatement();
String SQL=new String();
%>
<%
SQL="SELECT*FROM [user] WHERE [user]='"+ userid+"'";
ResultSet rs=stmt.executeQuery(SQL);
int flag=1;
if(rs.next()){
flag=0;
}
rs.close();
if(flag==1){
}
%>
<%
SQL="INSERT INTO [user](user，id，password，email，name，sex，work，ipnum) VALUES('"+userid+"'，'"+userid2+"','"+password+"','"+useremail+"','"+username+"','"+usersex+"','"+userwork+"',0)";
stmt.executeUpdate(SQL);
%>
<%String SQL2=new String();
SQL2="CREATE TBLE"+userid+"(title TEXT，article TEXT )";
stmt.close();
con.close();
}
catch(Exception e){
                System.out.println("操作数据库出错，请仔细检查");
                System.err.println(e.getMessage());
            }
%>
<p align="center"><b><font color="cc00cc" face="宋体">注册成功！欢迎注册</font></b></p>
<p align="center"><b><font color="cc00cc" face="宋体">你注册的信息如下：</font></b></p>
<table width="200" border="0" cellspacing="0" cellpadding="0">
<tr>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">用户账号：</font></b></td>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">
<%=userid %></font></b></td></tr>
<tr>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">用户呢称：</font></b></td>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">
<%=userid2%></font></b></td>
</tr>
<tr>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">email：</font></b></td>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">
<%=useremail %></font></b></td>
</tr>
<tr>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">姓名：</font></b></td>
<td heigth="35" width="100"><b><font color="#9900ff" size="3"><%=username %></font></b></td></tr>
<tr>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">性别：</font></b></td>
<td heigth="35" width="100"><b><font color="#9900ff" size="3"><%=usersex %></font></b></td></tr>
<tr>
<td heigth="35" width="100"><b><font color="#9900ff" size="3">职业：</font></b></td>
<td heigth="35" width="100"><b><font color="#9900ff" size="3"><%=userwork %></font></b></td></tr>
</table>
<% }
else{
%>
<p align="center"><b><font face="宋体" color="#cc00cc" size="+2">这个用户名已经有人使用！</font></b></p>
<% }

%>
<% if(!(password.equals(password2))){
%>
<p align="center"><b><font face="宋体" color="#cc00cc" size="+2">密码不符！</font></b></p>
<%}

if(n==0){
%>
<p align="center"><b><font face="宋体" color="#cc00cc" size="+2">有未填的注册信息！</font></b></p>
<%}
%>
<p align="center"><b><font face="宋体" color="#cc00cc" size="+2">注册失败!
</font></b></p

</div>
</body>
</html>

6 个解决方案

#1

userid
userid2
password
password2
useremail
username
这其中一个或几个为空值。。。。。
检查下

#2

  userid2=request.getParameter("txtuserid2");
  password=request.getParameter("txtpassword");
  password2=request.getParameter("txtpassword2");
  useremail=request.getParameter("txtemail");
  username=request.getParameter("txtname");
  usersex=request.getParameter("radsex");
  userwork=request.getParameter("selwork");
这些方法中的参数你都没设置啊。。取出来的当然是空值了。。怪不得是空指针异常。。
你要从表单中取一个参数的值。。
如：<input type = "text" name =" txtuserid"/>
中的name属性值必须和你的userid=request.getParameter(" txtuserid"); 参数相同

#3

n=userid.length()*userid2.length()*password.length()*password2.length()*useremail.length()*username.length();
楼上非常正确

#4

同意而楼，你还没有给他变量，怎么得到值呢？

#5

顶２楼，是啊，你没有用到表单中的input控件，也没有设置name的值，
request.getParameter()方法去哪里拿到你的输入的数据啊，肯定是空的

#6

有啊有设置的前面有个这样的文档
做了相应的定义啊  相应的属性值也没错啊这是一个注册页面填好相应的数据后点击确认按钮跳转到这个页面显示注册的信息
就是从那个跳转到这个页面的时候就不行了  谢谢你的指点但是我觉得不是这里的问题吧能在帮我看看好吗？
上一页面程序如下：
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>注册窗口</title>
<meta http-equiv="content-type" content="text/html; charset=gb2312">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="this is my page">
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">

    

  </head>

  <body bgcolor="000ffff">
  <div align="center">
  <p></font size="5" face="隶书"><b><font color="0000fffff">注册窗口</font></b></p>
  <hr>
  <p align="left"><b><font color="cc00cc" face="隶书">请输入注册信息：</font></b></p>
  <form method="middle" action="zhuce2.jsp">
  <table border="0" cellspacing="0" align="center">
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">用户账号：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="text" name="txtuserid" size="20" maxlength="12">*不能为空
  </font></b></div>
  </td>
  </tr>
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">用户呢称：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="text" name="txtuserid2" size="20" maxlength="12">
  </font></b></div>
  </td>
  </tr>
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">用户密码：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="password" name="txtpassword" size="20" maxlength="12">*必须是1~9的数字或者字母
  </font></b></div>
  </td>
  </tr>
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">密码确认：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="password" name="txtpassword2" size="20" maxlength="12">
  </font></b></div>
  </td>
  </tr>
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">EMAIL：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="text" name="txtemail" size="20" maxlength="12">*请填写正确的EMAIL
  </font></b></div>
  </td>
  </tr>
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">真实姓名：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="text" name="txtname" size="20" maxlength="12">*必须填写
  </font></b></div>
  </td>
  </tr>
  <tr valign="middle" align="left">
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">用户性别：</font></b></div>
  <td height="35" width="100">
  <div align="left"><b><font size="2" color="9900ff">
  <input type="radio" name="radsex" value="male"checked>男
  <input type="radio" name="radsex" value="female" >女
  </font></b></div>
  </td>
  </tr>
  <tr>
<tr valign="middle" align="left">
  <td height="35" width="100"><b><font size="2" color="9900ff">你的职业：</font></b></td>
   <td height="35" width="100"><b><font size="2" color="9900ff">
   <select name="selwork">
   <option value="STUDENT">学生</option>
    <option value="TEACHER">教师</option>
     <option value="MERCHANT">商人</option>
      <option value="CADRE">*</option>
       <option value="ORHTER">其他</option>
       </select>
       </font></b></td>
       </tr>
       <tr align="middle" align="left">
       <td heitght="35" colspan="2" >
       <div align="left"></div>
       <div align="center">
       <input type="submit" name="cmdok" value="确认">
        <input type="reset" name="cmdreset" value="重置">
        </div>
        </td>
        </tr>
        </table>
        </form>
       <p> </p>
       </div>
  </body>
</html>

#1

userid
userid2
password
password2
useremail
username
这其中一个或几个为空值。。。。。
检查下

#2

#3

n=userid.length()*userid2.length()*password.length()*password2.length()*useremail.length()*username.length();
楼上非常正确

#4

同意而楼，你还没有给他变量，怎么得到值呢？

#5

顶２楼，是啊，你没有用到表单中的input控件，也没有设置name的值，
request.getParameter()方法去哪里拿到你的输入的数据啊，肯定是空的

秒客网

JSP连接数据库的问题刚刚学不知道错误怎么改望高手教我

6 个解决方案

#1

#2

#3

#4

#5

#6

#1

#2

#3

#4

#5

#6

相关文章

JSP连接数据库的问题 刚刚学不知道错误怎么改 望高手教我

6 个解决方案

#1

#2

#3

#4

#5

#6

#1

#2

#3

#4

#5

#6

相关文章

JSP连接数据库的问题刚刚学不知道错误怎么改望高手教我