Passwort-Pruefer-Profis/src/Credentials.java

import org.junit.jupiter.api.Test;

public class Credentials {

    private String login;
    private String hash;

    public Credentials(String login, String password) {
        this.hash = Helpers.getHash(password);
        this.login = login;
    }

    public boolean valid() {

        boolean usernameGiven = false;
        String hashData;

        //iterator over file
        for (String line:
                Helpers.readTextdatei("data/passwd.txt")) {
            if(login == line) {
                usernameGiven = true;
                continue;
            }
            if(usernameGiven && hash == line) {
                return true;
            }

        }
        return false;
    }
}