java swing with functional/declarative programming logic error

Question

I'm trying to make a login function in java swing with functional programming style, below is my code

String username = txtUsername.getText();
        String passwordStr = String.valueOf(txtPassword.getPassword());
        User login = new User(username, passwordStr);

        Optional<User> adminUser = Optional.of(new User("a", "a"));
        Optional<User> user = Optional.ofNullable(login);

        adminUser.filter(u -> u.equals(login))
                .ifPresentOrElse(
                        u -> {
                            this.setVisible(false);
                            HomePageAdmin hma = new HomePageAdmin();
                            hma.setVisible(true);
                        },
                        () -> user.filter(u -> u.login(passwordStr))
                                .ifPresentOrElse(
                                        u -> {
                                            this.setVisible(false);
                                            HomePagePeople hmp = new HomePagePeople(username);
                                            hmp.setVisible(true);
                                        },
                                        () -> JOptionPane.showMessageDialog(null, "Wrong Credential")
                                )
                );

everything is working fine, if I try to login with credentials other than "a" as username and "a" as password, however when I try to log in to the system with those credentials, it gives the "wrong credential" Pane as seen below

I also tried various ways with the filter function above with this alternatives

        User login = new User(username, passwordStr);
        User loginAdmin = new User("a", "a");

        Optional<User> adminUser = Optional.of(loginAdmin);
        Optional<User> user = Optional.ofNullable(login);

        adminUser.filter(u -> u.equals(login))

the code above give the same error and won't accept the logic. However, if I try to change the adminUser.filter(u -> u.equals(login)) to adminUser.filter(u -> u.equals(loginAdmin)), it works just fine, however this logic is wrong as the adminUser will always be equal to loginAdmin thus inputting anything into the textbox will allow user to log in to the admin page as seen in example below

any help is greatly Appreciated

Answer 1

I fixed my problem by implementing the same logic with the user.filter(u -> u.login(passwordStr)) code by creating a new method in my User class called loginAdmin as seen below

public boolean loginAdmin(String name, String pw) {

        //file to be scanned 
        String Temp = "a";
        String Temp2 = "a";
        //returns true if there is another line to read  

        if (Temp.equals(Username) && Temp2.equals(Password)) {
            return true;
        } else {
            return false;

        }
    }

this fix the problem and is implemented to the login class and here's the updated code

String Username = txtUsername.getText();
        String Password = String.valueOf(txtPassword.getPassword());
        User login = new User(Username, Password);

        Optional<User> adminUser = Optional.of(login);
        Optional<User> user = Optional.ofNullable(login);

        adminUser.filter(u -> u.loginAdmin(Username, Password))
                .ifPresentOrElse(
                        u -> {
                            this.setVisible(false);
                            HomePageAdmin hma = new HomePageAdmin();
                            hma.setVisible(true);
                        },
                        () -> user.filter(u -> u.login(Password))
                                .ifPresentOrElse(
                                        u -> {
                                            this.setVisible(false);
                                            HomePagePeople hmp = new HomePagePeople(Username);
                                            hmp.setVisible(true);
                                        },
                                        ()
                                        -> JOptionPane.showMessageDialog(null, "Wrong Credential")
                                )
                );

Thanks everyone for helping me with this issue