登陆不进去,但是添加记录却可以,问题何在?我把代码萜出来,哪位大虾能看到,请指教~~~~~~急急急``

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login_confirm.javaimport test.*;
import test.sqlBean;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;public class login_confirm extends HttpServlet{
 public void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
        
   String message=null;    String id=null;
   id=req.getParameter("id");
   HttpSession session=req.getSession(true);
   session.setAttribute("id",String.valueOf(id));   String password=null;
   password= req.getParameter("password");
   HttpSession session1=req.getSession(true);
   session1.setAttribute("password",String.valueOf(password));
 
   String kind =null;
   kind=req.getParameter("kind");
   HttpSession session2=req.getSession(true);
   session2.setAttribute("kind",String.valueOf(kind));   String temp =getPassword(req,res,id,kind);
   if( password.equals(temp))
   goo(req,res,kind);
   else {
   message="用户名或密码有误！";
   doError(req,res,message) ;
  }
  } 
  
public void goo(HttpServletRequest req, HttpServletResponse res,String kind)
throws ServletException,IOException
{ if(kind.equals("student")) {
RequestDispatcher rd = getServletContext().getRequestDispatcher("/student.jsp");
    rd.forward(req, res);}
    if(kind.equals("teacher")){
     RequestDispatcher rd = getServletContext().getRequestDispatcher("/teacher.jsp");
    rd.forward(req, res);}
    if(kind.equals("admin")){
     RequestDispatcher rd = getServletContext().getRequestDispatcher("/admin.jsp");
    rd.forward(req, res);}
}
  
     
  public String getPassword(HttpServletRequest req, HttpServletResponse res,
                        String id,String kind)
                        throws ServletException, IOException {
   sqlBean db= new sqlBean();                  
   String pw="";                                           
   String sql="select password from "+kind+" where id='"+id+"'";
   try{
   ResultSet rs=db.executeQuery(sql); 
   if(rs.next() ){
     pw= rs.getString("password");
    }
    } 
    catch(Exception e)
{ System.out.print(e.toString());}        
    return pw; 
                            }
     
     
      
     public void doError(HttpServletRequest req,
                      HttpServletResponse res,
                      String str)
                      throws ServletException, IOException {    req.setAttribute("problem", str);
    RequestDispatcher rd = getServletContext().getRequestDispatcher("/errorpage.jsp");
    rd.forward(req, res);
  }
  
  
  public void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
      String action = action = req.getParameter("action");
      if ("logout".equalsIgnoreCase(action)) {
      HttpSession session=req.getSession(true);
        session.invalidate();
        RequestDispatcher rd = getServletContext().getRequestDispatcher("/login.jsp");
        rd.forward(req, res);
    } }
  
}
问题就是登陆不进去,一直提示用户名或者密码错误.