README.md

/**
 * Check if the username if registered
 *
 * @param username the username to try
 *
 * @return the status of how the command went
 */
public static String execute(String username)
{
    if(AccountUtil.isRegistered(username))
        return "331 Please specify the password.";
    else
        return "530 User not registered. This server can be accessed by anonymous";
}
private static Server server;
public static Server getServer() { return server; }


public static void main(String[] args)
{
    /* on remplit la "base de données" de compte pour la démo */

    AccountUtil.setAccounts("rayane", new Account("rayane", "hamani"));
    AccountUtil.setAccounts("florian", new Account("florian", "dendoncker"));
    AccountUtil.setAccounts("anonymous", new Account("anonymous", ""));

    /* on démarre le serveur */

    try
    {
        if(args.length>0)
            server = new Server(Integer.parseInt(args[0]));
        else
            server = new Server(21);

        new Thread(server).start();
    }

    catch(IOException e) { System.out.println("Failed to open the server."); }

    /* on attend l'instruction de l'utilisateur fermer le serveur */

    Scanner scanner = new Scanner(System.in);
    while(true)
    {
        if(scanner.next().toLowerCase().equals("stop"))
        {
            scanner.close();
            System.exit(0);
        }
    }
}
/**
 * Accept connections (multi-threaded)
 */
public void run()
{
    while(true)
    {
        try
        {
            new Thread(new Connection(serverSocket.accept())).start();
            System.out.println("Connexion établie !");
        }

        catch(IOException e)
        {
            // nothing, we can to continue accepting connections
        }
    }
}
/**
 * Run the connection
 * Ask to login first before letting the user execute other commands
 *
 */
public void run()
{
    String response;

    response = "220 Service ready for a new user.";
    send(response);

    /* On force la connexion */

    while (isRunning && !isLogged) {
        response = login();
        send(response);
    }

    /* On exécute les commandes de l'utilisateur */

    while (isRunning && isLogged) {
        response = execute();
        send(response);
    }

    /* on ferme les ressources liées à cette connexion */

    Quit.execute(this);
}
/**
 * Receive and execute the only acceptable commands when a user is not logged
 * yet. The only acceptable commands are AUTH, USER, PASS and QUIT. They should
 * be enough for the user to log in
 *
 * @return the status of how the command went
 */
public String login()
{
    String response;

    try
    {
        String[] command = reader.readLine().split(" ");

        switch(command[0].toUpperCase())
        {
        case "AUTH":
            response = Auth.execute();
            break;
        case "USER":
            response = User.execute(command[1]);
            if (User.isSuccessful(response))
                this.username = command[1];
            break;
        case "PASS":
            response = Pass.execute(this.username, command[1]);
            if(Pass.isSuccessful(response))
                this.isLogged = true;
            else
                this.isRunning = false;
            break;
        case "QUIT":
            response = Quit.execute(this.isRunning);
            break;
        default:
            response = "530 Please login with USER and PASS.";
            break;
        }
    }

    catch(IOException e)
    {
        response = "500 The read of the command failed. Try again please.";
    }
    catch(NullPointerException e)
    {
        response = Quit.execute(this.isRunning);
    }

    return response;
}