Java可运行应用程序sinlgeton问题

我在使用单例时遇到了一个问题，我将在代码之后解释这个问题

类启动器

    public class Launcher {

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                Controleur ctr = Controleur.getInstance();
            }
        });
    }
}

public class Controleur {
    @SuppressWarnings("unused")
    private EcranPrincipal EP;
    private PremierEcran PE;

    public Controleur() {

        if(!VerifierFichier()){
            PE = new PremierEcran();
            PE.setVisible(true);
        }
        else
            lancerEcranPrincipal();
    }

    private static Controleur INSTANCE = null;

    public static Controleur getInstance(){
        if(INSTANCE == null){
            INSTANCE = new Controleur();
        }
        return INSTANCE;
    }

    public void lancerEcranPrincipal(){
        try{
            PE.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        }catch(Exception e){}

        EP = new EcranPrincipal();
    }

    public void setMDP(String mdp1){
        new MotDePasse(mdp1);
    }

    public void setVille(String nomVilleFormat) {
        FichierVille.getInstance(nomVilleFormat);
    }

    public String getNomVille() {
        String nomVille = FichierVille.getInstance("").getNomFichier();
        return "";
    }

    public boolean VerifierFichier(){
        File mdpfile;

        mdpfile = new File("data/MotDePasse.dat");
        if(mdpfile.exists() && mdpfile.isFile()){
            JOptionPane.showMessageDialog(null, "true");
            return true;
        }
        else{
            JOptionPane.showMessageDialog(null, "false");
            return false;
        }
    }
}

class Controleur

    public class Launcher {

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                Controleur ctr = Controleur.getInstance();
            }
        });
    }
}

public class Controleur {
    @SuppressWarnings("unused")
    private EcranPrincipal EP;
    private PremierEcran PE;

    public Controleur() {

        if(!VerifierFichier()){
            PE = new PremierEcran();
            PE.setVisible(true);
        }
        else
            lancerEcranPrincipal();
    }

    private static Controleur INSTANCE = null;

    public static Controleur getInstance(){
        if(INSTANCE == null){
            INSTANCE = new Controleur();
        }
        return INSTANCE;
    }

    public void lancerEcranPrincipal(){
        try{
            PE.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        }catch(Exception e){}

        EP = new EcranPrincipal();
    }

    public void setMDP(String mdp1){
        new MotDePasse(mdp1);
    }

    public void setVille(String nomVilleFormat) {
        FichierVille.getInstance(nomVilleFormat);
    }

    public String getNomVille() {
        String nomVille = FichierVille.getInstance("").getNomFichier();
        return "";
    }

    public boolean VerifierFichier(){
        File mdpfile;

        mdpfile = new File("data/MotDePasse.dat");
        if(mdpfile.exists() && mdpfile.isFile()){
            JOptionPane.showMessageDialog(null, "true");
            return true;
        }
        else{
            JOptionPane.showMessageDialog(null, "false");
            return false;
        }
    }
}

班主任

public class EcranPrincipal extends JFrame{
 public EcranPrincipal(){
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setAlwaysOnTop(true);
            setExtendedState(JFrame.MAXIMIZED_BOTH);
            setUndecorated(true);
            getContentPane().setBackground(Color.white);

            JPanel pane = new JPanel();
            GridBagLayout gridbag = new GridBagLayout();
            pane.setLayout(gridbag);
            pane.setBackground(Color.white);

            JTextPane Textmdp = new JTextPane();
            String name = Controleur.getInstance().getNomVille();
            Textmdp.setText("ville: ");
            Textmdp.setEditable(false);
    }
 }

当singleton已经实例化时，在类“EcranPrincipal”中，我将类的实例singleton称为“controleur”：

这里最大的问题是这一行，因为它给出了这一行的执行结果

JOptionPane.showMessageDialog(null, "true");

谁在“Controleur”类的Function VerifierFichier（）中。因此，我有无限次的showmessage对话框。我的问题是为什么我的单身汉没有按照我想要的那样执行。 确切地说，我希望我的变量“name”去获取函数“getNomVille（）”中的信息

请帮帮我

提前谢谢