插入数据库出错，新手求教

[qq280159235]

错误是：The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
cn.wy.CtrlServlet.Reg.processRequest(Reg.java:63)
cn.wy.CtrlServlet.Reg.doPost(Reg.java:86)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)


note The full stack trace of the root cause is available in the Apache Tomcat/6.0.35 logs.
源码：
DBConnection dbc=null;
String userEmail;
String userName;
String userPwd;
//int userSex;
//Date userbirthday = null;
//String userSchool;
response.setContentType("text/html;charset=UTF-8");
out = response.getWriter();
try{ dbc = new DBConnection();
PreparedStatement ps = null;
userEmail = request.getParameter("userEmail");
userName = request.getParameter("userName");
userPwd = request.getParameter("userPwd");
System.out.print(userEmail);
System.out.print(userName);
System.out.print(userPwd);
//userSex = Integer.parseInt(request.getParameter("userSex"));

//userSchool = request.getParameter("userSchool");
if (userName != null && userPwd != null && userEmail != null)
{
ps = dbc.getCon().prepareStatement("insert into ceshi (userEmail,userName,userPwd)" +" values(?,?,?)");
ps.setString(1, userEmail);
ps.setString(2, userName);
ps.setString(3, userPwd);
// //ps.setDate(5, userbirthday);
//ps.setInt(4, userSex);
ps = dbc.getCon().prepareStatement("insert into ceshi values(userEmail,userName,userPwd)");
ps.execute();
System.out.print("新用户注册：" + request.getParameter("userName") + " ");
out.print("<script>alert('恭喜您：注册成功！现已经登录到网站！');history.go(-1)</script>");
}
if (dbc != null)
dbc.dbClose();
}
catch(SQLException ex)
{ out.print("<script>alert('注册失败！数据库连接错误！');history.go(-1)</script>");
ex.printStackTrace();
if (dbc != null)
dbc.dbClose(); }
}

[quanwe]

施主...调试下吧...明显告诉你是NullPointerException ...

[quanwe]

或者重启去吧

[iGoodLoser]

空指针异常cn.wy.CtrlServlet.Reg.processRequest(Reg.java:63)63行，分析下吧，别人帮不了你

[YAVA_2009]

首先，看你要写的几个值打印出来都不是null
其次，看看你数据库字段设的属性是什么，是否长度不够

[huaihuaidexiao]

看看这行附近的变量在使用前是不是忘记赋值了。

cn.wy.CtrlServlet.Reg.processRequest(Reg.java:63)

空指针异常 基本上都是这个原因。

[qq280159235]

[Quote=引用 4 楼 的回复:]

首先，看你要写的几个值打印出来都不是null
其次，看看你数据库字段设的属性是什么，是否长度不够
[/Quote]我写的那几个值都不为空；这句话有错，没看出哪里错了ps = dbc.getCon().prepareStatement("insert into ceshi (userEmail,userName,userPwd)" +" values(?,?,?)");

[cxw3152]

空指针异常 跟踪一下你的代码 应该很快就解决了 。。