checklogin.jsp

用jsp写的毕业设计管理系统

<%@page import="java.util.*" %> 
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<% 
int a=0;
 String rand = (String)session.getAttribute("rand");
 String input = request.getParameter("checknum");
%>
<br>
<%
  if (rand.equals(input)) {
  a=1;
  }
%>
<% 
String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
String url = "jdbc:odbc:bbs";
try{
  Class.forName(driver);
  Connection conn = DriverManager.getConnection(url,"sa","sa");
  String sql = "select * from user_Info where username='"+request.getParameter("username")+"'";
  //out.println(sql);
  String pwd="";
  //int flag;
  Statement stmt = conn.createStatement();
  ResultSet rs = stmt.executeQuery(sql);
  if(rs.next())
  {
   pwd=(rs.getString(3)).trim();
   
   String pwd1=(request.getParameter("password")).trim();
   //flag=(int)(rs.getInt(4));

   if(pwd1.equals(pwd)&&a==1){
      response.sendRedirect("index.jsp"); 	
 	 }
  else if(!pwd1.equals(pwd)){
  %>
   <script language="javascript">
  alert("密码错误");
  window.history.go(-1);
  </script>
  <%} 
  else if(a!=1){
  %>
 
  <script language="javascript">
  alert("验证码错误");
  window.history.go(-1);
  </script>
  <%}
  }
  else
  {
  
  %>
  <script language="javascript">
  alert("用户名错误");
  window.history.go(-1);
  </script> 
  <%}
}catch(Exception e)
{
  System.out.println(e.getMessage());
}


%>