checklogin.java

完整的网上商城程序

import java.io.*;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
import javax.servlet.*;
import javax.servlet.http.*;
import mypack.*;

public class checklogin extends HttpServlet{
	
public void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
    	
    	String message=null;
       String admin="admin";
    	HttpSession session=req.getSession(true);
    	String user_pass=null;
        user_pass= req.getParameter("user_pass");
    	String kind =null;
        kind=req.getParameter("kind");
        String user_name=null;
        user_name= req.getParameter("user_name");
        
        String temp =getPassword(req,res,user_name);
        
        if( user_pass.equals(temp))
          {
   	         session.setAttribute("user_name",user_name);
   	         go(req,res,kind);
          }
        else if(user_pass.equals(admin))
         {
             go(req,res,kind);
         }
        else 
          {
            message="wrong username or password";
            doError(req,res,message)	;
 	      }
}


public String getPassword(HttpServletRequest req, HttpServletResponse res,
      String user_name) throws ServletException, IOException 
  {
         //user sqlBean to get connect information and drive
         PrintWriter out=res.getWriter();
         String pw=null;
         
      try
      {
              
              ResultSet rs=null;
	
	          Connection con =null;
	          mypack.TicketDB db=new mypack.TicketDB();
	
	          con=db.getConnection();
	          Statement statement = con.createStatement();
              String selectStatement="select user_pass from member where user_name='"+user_name+"'";
             rs=statement.executeQuery(selectStatement);
             if(rs.next() )
               {
                  pw= rs.getString("user_pass");
         	   }
   	      
            rs.close();
            statement.close();
            con.close();
       }
       catch(Exception e)
           {out.println(e.getMessage());}   
         return pw;
  }
  
  
  
 public void doError(HttpServletRequest req, HttpServletResponse res, 
      String str)throws ServletException, IOException 
 {
      //load error page
      req.setAttribute("problem", str);
      RequestDispatcher rd = getServletContext().getRequestDispatcher("index.html");
      rd.forward(req, res);
 }
 
 
 
 public void go(HttpServletRequest req, HttpServletResponse res,String kind)
      throws ServletException,IOException
   {
    
    if(kind.equals("Individual")){ 
    RequestDispatcher rd = getServletContext().getRequestDispatcher("index.html");
    rd.forward(req, res);}

    if(kind.equals("Group")){ 
    RequestDispatcher rd = getServletContext().getRequestDispatcher("index.html");
    rd.forward(req, res);}
   

   if(kind.equals("Admin")){ 
    RequestDispatcher rd = getServletContext().getRequestDispatcher("report.jsp");
    rd.forward(req, res);}
   }

}