JOptionPane pour obtenir le mot de passe

La chose La plus facile est d'utiliser JOptionPane's showConfirmDialog méthode et de passer une référence à un JPasswordField; par exemple,

JPasswordField pf = new JPasswordField();
int okCxl = JOptionPane.showConfirmDialog(null, pf, "Enter Password", JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE);

if (okCxl == JOptionPane.OK_OPTION) {
  String password = new String(pf.getPassword());
  System.err.println("You entered: " + password);
}

Modifier

Voici un exemple d'utilisation d'un JPanel personnalisé pour afficher un message avec le JPasswordField. Selon le commentaire le plus récent, j'ai également (à la hâte) ajouté du code pour permettre au JPasswordField de se concentrer lorsque la boîte de dialogue est affichée pour la première fois.

public class PasswordPanel extends JPanel {
  private final JPasswordField passwordField = new JPasswordField(12);
  private boolean gainedFocusBefore;

  /**
   * "Hook" method that causes the JPasswordField to request focus the first time this method is called.
   */
  void gainedFocus() {
    if (!gainedFocusBefore) {
      gainedFocusBefore = true;
      passwordField.requestFocusInWindow();
    }
  }

  public PasswordPanel() {
    super(new FlowLayout());

    add(new JLabel("Password: "));
    add(passwordField);
  }

  public char[] getPassword() {
      return passwordField.getPassword();
  }

  public static void main(String[] args) {
      PasswordPanel pPnl = new PasswordPanel();
      JOptionPane op = new JOptionPane(pPnl, JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE);

      JDialog dlg = op.createDialog("Who Goes There?");

      // Wire up FocusListener to ensure JPasswordField is able to request focus when the dialog is first shown.
      dlg.addWindowFocusListener(new WindowAdapter() {
        @Override
        public void windowGainedFocus(WindowEvent e) {
            pPnl.gainedFocus();
        }
      });

      if (op.getValue() != null && op.getValue().equals(JOptionPane.OK_OPTION)) {
          String password = new String(pPnl.getPassword());
          System.err.println("You entered: " + password);
      }
  }
}

Vous pouvez créer votre propre boîte de dialogue qui étend JDialog et ensuite vous pouvez y mettre ce que vous voulez.

Ce dialogue semble beaucoup mieux si vous ne

dlg.setVisible(true);

Sans cela, vous ne pouvez pas le voir du tout.

Aussi

pPnl.gainedFocus();

Devrait être

pPnl.gainedFocus();

Autre que cela fonctionne très bien. Merci pour le code. J'ai gagné du temps à faire face avec Swing.

Aussi, si vous ne voulez pas laisser le dialogue en arrière-plan chaque fois que vous l'ouvrez, vous devrez le fermer avec quelque chose comme

dlg.dispatchEvent(new WindowEvent(dlg, WindowEvent.WINDOW_CLOSING));
dlg.dispose(); // else java VM will wait for dialog to be disposed of (forever)

La classe suivante est une extension de Adamski la grande réponse:

package com.stackoverflow.swing;

import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;

/**
 * Class that creates a panel with a password field. Extension of Adamski's class
 *
 * @author adamski https://stackoverflow.com/users/127479/adamski
 * @author agi-hammerthief https://stackoverflow.com/users/2225787/agi-hammerthief
 * @see https://stackoverflow.com/a/8881370/2225787
 */
public class PasswordPanel extends JPanel {

  private final JPasswordField JFieldPass;
  private JLabel JLblPass;
  private boolean gainedFocusBefore;

  /**
   * "Hook" method that causes the JPasswordField to request focus when method is
   * first  called.
   */
  public void gainedFocus () {
    if (!gainedFocusBefore) {
      gainedFocusBefore = true;
      JFieldPass.requestFocusInWindow();
    }
  }

  public PasswordPanel (int length) {
    super(new FlowLayout());
    gainedFocusBefore = false;
    JFieldPass = new JPasswordField(length);
    Dimension d = new Dimension();
    d.setSize(30, 22);
    JFieldPass.setMinimumSize(d);
    JFieldPass.setColumns(10);
    JLblPass = new JLabel("Password: ");
    add(JLblPass);
    add(JFieldPass);
  }

  public PasswordPanel() {
    super(new FlowLayout());
    gainedFocusBefore = false;
    JFieldPass = new JPasswordField();
    Dimension d = new Dimension();
    d.setSize(30, 22);
    JFieldPass.setMinimumSize(d);
    JFieldPass.setColumns(10);
    JLblPass = new JLabel("Password: ");
    add(JLblPass);
    add(JFieldPass);
  }

  public char[] getPassword() {
    return JFieldPass.getPassword();
  }

  public String getPasswordString() {
    StringBuilder passBuilder = new StringBuilder();

    char[] pwd = this.getPassword();
    if (pwd.length > 0) {
      for (char c : pwd) {
        passBuilder.append(c);
      }
    }

    return passBuilder.toString();
  }

  private static String displayDialog (
    Component parent, final PasswordPanel panel, String title
  ) {
    String password = null;
    /* For some reason, using `JOptionPane(panel, JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE)`
    does not give the same results as setting values after creation, which is weird */
    JOptionPane op = new JOptionPane(panel);
    op.setMessageType(JOptionPane.QUESTION_MESSAGE);
    op.setOptionType(JOptionPane.OK_CANCEL_OPTION);
    JDialog dlg = op.createDialog(parent, title);
    // Ensure the JPasswordField is able to request focus when the dialog is first shown.
    dlg.addWindowFocusListener (new WindowAdapter () {
      @Override
      public void windowGainedFocus (WindowEvent e) {
        panel.gainedFocus ();
      }
    });
    dlg.setDefaultCloseOperation (JOptionPane.OK_OPTION); // necessary?

    dlg.setVisible (true);

    Object val = op.getValue ();
    if (null != val && val.equals (JOptionPane.OK_OPTION)) {
      password = panel.getPasswordString();
    }

    return password;
  }

  public static String showDialog (Component parent, String title) {
    final PasswordPanel pPnl = new PasswordPanel();
    return displayDialog(parent, pPnl, title);
  }

  public static String showDialog (
    Component parent, String title, int passwordLength
  ) {
    final PasswordPanel pPnl = new PasswordPanel(passwordLength);

    return displayDialog (parent, pPnl, title);
  }

  public static String showDialog (String title) {
    return showDialog(null, title);
  }

  public static String showDialog (String title, int passwordLength) {
    return showDialog(null, title, passwordLength);
  }

  /**
   * Show a test dialog
   */
  public static void main(String[] args) {
    String test = PasswordPanel.showDialog ("Enter Your Password");
    System.out.println ("Entered Password: " + test);
    System.exit(0);
  }

}