登陸出錯，求大佬幫忙
代碼如下：
<%@ page contentType="text/html; charset=GB2312" %>
<%@ page import="java.sql.*" %>
<%@ page language="java" %>
<%@ page import="java.util.*" %>
<html>
<head>
<title>
身份驗證
</title>
</head>
<body bgcolor="#ffffff">
<% request.setCharacterEncoding("GBK");
String user=request.getParameter("username");
String pwd=request.getParameter("password");
String sel=request.getParameter("select");
String url ="jdbc:odbc:yuqingpeng";
String userName = "sa";
String password = "123456";
String URL="";
String sql="";
Connection conn = null;
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}
catch(ClassNotFoundException e)
{
out.println("加載驅動器類時出現例外");
}
try {
conn = DriverManager.getConnection(url, userName, password);
//創建Statement陳述句
}
catch(SQLException e)
{
out.println("連接資料庫的程序中出現SQL例外<br>");
}
Statement stmt = conn.createStatement();
if(sel.equals("student")){
sql = "SELECT * FROM student where stu_id='"+user+"' and password='"+pwd+"'";
URL="student.jsp";
ResultSet rs = stmt.executeQuery(sql);
if(rs.next()){
String a=rs.getString("name");
request.getSession(true);
session.setAttribute("name",a);
session.setAttribute("id",user);
response.sendRedirect(URL) ;}
else
response.sendRedirect("error.jsp") ;
}
else if(sel.equals("admin")){
sql = "SELECT * FROM admin where admin_id='"+user+"' and password='"+pwd+"'";
URL="admin.jsp";
ResultSet rs = stmt.executeQuery(sql);
if(rs.next()){
request.getSession(true);
session.setAttribute("id",user);
response.sendRedirect(URL) ;}
else
response.sendRedirect("error.jsp") ;
}
//使用executeQuery執行SQL查詢陳述句
%>
</body>
</html>
uj5u.com熱心網友回復：
Statement stmt = conn.createStatement(); 這一行報空指導例外了！你在conn初始化之后，列印一下conn物件，看看有沒有問題？
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標籤：Web 開發