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Jsp Login Page Problem

malik ge
Ranch Hand

Joined: May 13, 2011
Posts: 69
Hello.
I am trying to make a login page using jsp and servlet.
The user name and password is verified from database.

The problem is that the first userName and userPassword in database is verified correctly,
but when I try to enter the other userName and userPassword it did not login.


The code of index.jsp





ControllerServlet
Bear Bibeault
Author and ninkuma
Marshal

Joined: Jan 10, 2002
Posts: 61206
    
  66

You're doing it poorly and inefficiently.

What you are doing:
  • Fetching all users and comparing credentials.


  • What you should be doing:
  • Fetch the count of records where the username and password match the credentials. You should get 0 or 1.


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    Paul Clapham
    Bartender

    Joined: Oct 14, 2005
    Posts: 18570
        
        8

    Bear Bibeault wrote:What you are doing:
  • Fetching all users and comparing credentials.


  • Actually malik is redirecting to "Good" or "Bad" based on the first user fetched, which is why the bad and inefficient method doesn't even do what it's supposed to do. (Only the first user in the table ever gets to log in.) But yes, just fixing that code isn't the thing to do. The query returning a simple yes or no is much better.
    malik ge
    Ranch Hand

    Joined: May 13, 2011
    Posts: 69
    Thanks for the reply.

    I have corrected this problem by using this:

    and it worked fine.

    Now I want to know how to do it in an efficient manner, by using "mvc". So I don't have to write the code of connecting with the database again and again.

    Thanks.
    Bear Bibeault
    Author and ninkuma
    Marshal

    Joined: Jan 10, 2002
    Posts: 61206
        
      66

    Moving this code to the model would be a good step.

    Also, if you'd like to be more efficient and don't need the row data (if all you care about is whether the record exists or not) select count(*) will be more performant than select *. But if you need the data, select * is fine.
     
    I agree. Here's the link: http://aspose.com/file-tools
     
    subject: Jsp Login Page Problem