如何在不同的Jframe中获取文本字段值？

Question

I'm creating a program that uses several different interacting menus to allow the user to access different parts of the system. I'm using Netbeans to help with the coding.

At the moment I'm stuck on a task.

When a user logs into the system through a "login" form, the system validates the details, and that user is redirected to either a "user_details" or an "admin_menu" depending on the credentials. That much works fine. From there, the user is able to access a form that allows them to update their details which are already saved in the database.

The only way I've found to limit the simple user to update their details is to ask them to login again, and from there retrieve their details so that they can be updated. This process is messy, but it works.

with that in mind how do i retrieve whatever was imputed in the textfield "Username" that is located in the jform Login from another jform (User_details), the User_details jform only opens once the login is successful (once that occurs login is discarded and user_details is opened).

by the way i've done a lot of research but cant seem to find an answer to my problem.

here is part of my log in code :

String sql = "select * from user where Username =? and password=?";
        try {
            pst = con.prepareStatement(sql);
            pst.setString(1, username.getText());
            pst.setString(2, password.getText());
            rs = pst.executeQuery();

            int count = 0;
            while (rs.next()) {
                count = count + 1;
            }
            if (count == 1) {
                JOptionPane.showMessageDialog(null, "Access Granted");
                if ("manager@manage.com".equals(t.getText())) {
                    rs.close();
                    pst.close();
                    close();
                    Admin_menu am = new Admin_menu();
                    am.setVisible(true);
                } else {
                    rs.close();
                    pst.close();
                    close();
                    User_details M = new User_details();
                    M.setVisible(true);
                }
            } else {
                JOptionPane.showMessageDialog(null, "Incorrect Username or Password");
            }
        } catch (Exception ex) {
            JOptionPane.showMessageDialog(null, ex);

        } finally {
            try {
                rs.close();
                pst.close();
            } catch (Exception ex) {
            }
        }

---

how can i make the User_details Jform get what ever was imputed in the textfield username?

Answer 1

You will probably want to create some class which represents the state of everything a logged in user does in your application. Traditionally, you would call it a Session. The logged in user is a property of that session, so you keep it in a field there. You pass the session into every frame you make, so that they all have access to it.

The session becomes invalid when the user logs out.

Then from your frames, components, whatever, you can get the current user from the session.

But please, try to separate front-end from back-end code here. Look into the MVC pattern .

Answer 2

try to declare the variables public and initiailize them with the other jframes where you want to use them for example

public your class{

    initComponents();
    String a;


}

hope this helps :)

Answer 3

You could create a class "BasicView" in wich a class variable exists where you store your information, so every instance of this class can use ist. Then you just need to extend this basic class, or just use BasicView.value or BasicView.getValue(). Also you can use a synchronized method to change this var.

public class BasicView {
    private static Object value;

    public synchronized void setValue(Object value) {
        this.value = value;
    }

    public Oject getValue() {
        return value;
    }
    .
    .
    .
}

I use this to init an ServicesLocator to get servies in all my beans. :)

EDIT: Also take a look at the MVC pattern and use this in the controller (Basic Controller) or something like that.

Answer 4

1. Use Composition , and also make sure that your GUI class always returns the same Object when referenced from different JFrames.

2. This can be achieved using Singleton Principle .

Answer 5

Create a class called session like this:

public class Session {

    public static String userName = "";

}

When login happens set the value of Session.userName to the given userName and when the user logs out set Session.userName to "". You can access Session.userName simply by typing Session.userName. Other session variables should be defined in the Session class too.