在Java Servlet中使用会话

Question

can anyone tell me how to use sessions in login methods? here my loging code and its working correctly.need to put sessions for that and don't know how..

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    String operation = request.getParameter("operation");
    if(operation!=null && operation.equalsIgnoreCase("login")){
        loginDetail(request,response);
    }//else if(operation!=null && operation.equalsIgnoreCase("login")){
        //logout(request,response);
    //}
}

private void loginDetail(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{


    User u = new User();
    UserService us =new UserServiceImpl() ;

    String Uname = request.getParameter("txtUname");        
    String Pwrd = request.getParameter("txtPwrd");  

    u.setUname(Uname);
    u.setPwrd(Pwrd);

    System.out.println(Uname+""+Pwrd);
    try {
        if(us.Userlogin(u.getUname(),u.getPwrd())){     
            String message = "Thank you, " + Uname +"..You are now logged into the system";
            HttpSession session = request.getSession(true);
            session.setAttribute("username", Uname);
            session.setAttribute("password", Pwrd);         
            response.setContentType("text/html");
            request.setAttribute("message", message);
            request.getRequestDispatcher("/Menu.jsp").forward(request, response);
        }else {
            String message = "You have to register first or check Your user name password again!";              
            request.setAttribute("loginMsg", message);
            RequestDispatcher rd = getServletContext().getRequestDispatcher("/Login.jsp");
            rd.forward(request, response); 
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block          
        e.printStackTrace();
    }
}
}

I just put some lines of code inside "if(us.Userlogin(u.getUname(),u.getPwrd()))" statement..guide me through this piece of code

Answer 1

Did you mean that you want to login via the code you mentioned, and next time you don't want to login again to access the functionalities? So, you need to put a flag indicating the login status in the session object which span the life cycle of a specific time, eg, 30 minute. And the you put a filter to query the flag every time a request comes to determine if the client has logged. It would be useful if you are doing a project for learning purpose.