java 数据传递？ 两个对话框之间

简介

java 数据传递，简单通过类对象传递？
两个对话框之间

Q&A

但是不知道是如何实现模态的对话框的，看了几遍也还不知道？
JDialog 第二个参数就是模态和非模态的选择

code

package dataExchange;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
 * A frame with a menu whose File->Connect action shows a password dialog.
 */
public class DataExchangeFrame extends JFrame {
   public static final int TEXT_ROWS = 20;
   public static final int TEXT_COLUMNS = 40;
   private PasswordChooser dialog = null;
   private JTextArea textArea;

   public DataExchangeFrame() {
      // construct a File menu

      var mbar = new JMenuBar();
      setJMenuBar(mbar);
      var fileMenu = new JMenu("File");
      mbar.add(fileMenu);

      // add Connect and Exit menu items

      var connectItem = new JMenuItem("Connect");
      connectItem.addActionListener(new ConnectAction());
      fileMenu.add(connectItem);

      // the Exit item exits the program

      var exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(event -> System.exit(0));
      fileMenu.add(exitItem);

      textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
      add(new JScrollPane(textArea), BorderLayout.CENTER);
      pack();
   }

   /**
    * The Connect action pops up the password dialog.
    */
   private class ConnectAction implements ActionListener {
      public void actionPerformed(ActionEvent event) {
         // if first time, construct dialog

         if (dialog == null)
            dialog = new PasswordChooser();

         // set default values
         dialog.setUser(new User("yourname", null));

         // pop up dialog
         if (dialog.showDialog(DataExchangeFrame.this, "Connect")) {
            // if accepted, retrieve user input
            User u = dialog.getUser();
            textArea.append("user name = " + u.getName() + ", password = " + (new String(u.getPassword())) + "
");
         }
      }
   }
}

/*
 * @Author: your name
 * @Date: 2020-11-08 14:59:28
 * @LastEditTime: 2020-11-08 15:00:13
 * @LastEditors: your name
 * @Description: In User Settings Edit
 * @FilePath: /java/dataExchange/DataExchangeTest.java
 */
package dataExchange;

import java.awt.*;
import javax.swing.*;

/**
 * @version 1.35 2018-04-10
 * @author Cay Horstmann
 */
public class DataExchangeTest {
   public static void main(String[] args) {
      EventQueue.invokeLater(() -> {
         var frame = new DataExchangeFrame();
         frame.setTitle("DataExchangeTest");
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
      });
   }
}

package dataExchange;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Frame;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

/**
 * A password chooser that is shown inside a dialog.
 */
public class PasswordChooser extends JPanel {
   private JTextField username;
   private JPasswordField password;
   private JButton okButton;
   private boolean ok;
   private JDialog dialog;

   public PasswordChooser() {
      setLayout(new BorderLayout());

      // construct a panel with user name and password fields

      var panel = new JPanel();
      panel.setLayout(new GridLayout(2, 2));
      panel.add(new JLabel("User name:"));
      panel.add(username = new JTextField(""));
      panel.add(new JLabel("Password:"));
      panel.add(password = new JPasswordField(""));
      add(panel, BorderLayout.CENTER);

      // create Ok and Cancel buttons that terminate the dialog

      okButton = new JButton("Ok");
      okButton.addActionListener(event -> {
         ok = true;
         dialog.setVisible(false);
      });

      var cancelButton = new JButton("Cancel");
      cancelButton.addActionListener(event -> dialog.setVisible(false));

      // add buttons to southern border

      var buttonPanel = new JPanel();
      buttonPanel.add(okButton);
      buttonPanel.add(cancelButton);
      add(buttonPanel, BorderLayout.SOUTH);
   }

   /**
    * Sets the dialog defaults.
    * 
    * @param u the default user information
    */
   public void setUser(User u) {
      username.setText(u.getName());
   }

   /**
    * Gets the dialog entries.
    * 
    * @return a User object whose state represents the dialog entries
    */
   public User getUser() {
      return new User(username.getText(), password.getPassword());
   }

   /**
    * Show the chooser panel in a dialog.
    * 
    * @param parent a component in the owner frame or null
    * @param title  the dialog window title
    */
   public boolean showDialog(Component parent, String title) {
      ok = false;

      // locate the owner frame

      Frame owner = null;
      if (parent instanceof Frame)
         owner = (Frame) parent;
      else
         owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);

      // if first time, or if owner has changed, make new dialog

      if (dialog == null || dialog.getOwner() != owner) {
         dialog = new JDialog(owner, true);
         dialog.add(this);
         dialog.getRootPane().setDefaultButton(okButton);
         dialog.pack();
      }

      // set title and show dialog

      dialog.setTitle(title);
      dialog.setVisible(true);
      return ok;
   }
}

package dataExchange;

/**
 * A user has a name and password. For security reasons, the password is stored
 * as a char[], not a String.
 */
public class User {
   private String name;
   private char[] password;

   public User(String aName, char[] aPassword) {
      name = aName;
      password = aPassword;
   }

   public String getName() {
      return name;
   }

   public char[] getPassword() {
      return password;
   }

   public void setName(String aName) {
      name = aName;
   }

   public void setPassword(char[] aPassword) {
      password = aPassword;
   }
}