check.jsp

这是一个在线教育系统

<%@ include file="conn.jsp"%>
<%request.setCharacterEncoding("GB2312");
String username="";
username=request.getParameter("username");
 password=request.getParameter("password");
if(username==null){
 out.print("<SCRIPT language=JavaScript>alert('请输入您的登录名！');");
   out.print("history.go(-1);</SCRIPT>"); 
}
if(password==null){
 out.print("<SCRIPT language=JavaScript>alert('请输入密码！');");
   out.print("history.go(-1);</SCRIPT>"); 
}
String sql="select * from scott.teacher where loginname = '" + username + "' and password= '" + password + "'"; 
ResultSet rs=stmt.executeQuery(sql); 
 if(!rs.next()){
out.print("<script>alert('登录名或密码输入错误，没有该教师');history.go(-1);</script>");
 }else{
	 session.putValue("teacherid",rs.getString("teacherid")); 
	 session.putValue("admin","user"); 
 response.sendRedirect("teachermain.jsp"); 
 }
%>