Java Swing中JDialog实现用户登陆UI示例

package awtDemo;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
/*
 * @功能：使用JDialog构造登陆对话框，并获取登陆用户信息
 * @版本：20150804
 * @结构：LoginDemoStart[主类，提供初始UI]，PasswordChooser[提供登陆UI并获取用户信息]，User[保存用户信息]
 */
@SuppressWarnings("serial")
class LoginDemoStart extends JFrame{
  /*
   * @功能：提供初始UI，并调用PasswordChooser登陆界面
   * @版本：20150804
   */
  private JTextArea textArea;
  private PasswordChooser passwordChooser ;
  public LoginDemoStart(){
    //构造菜单栏
    JMenuBar mbar = new JMenuBar();
    setJMenuBar(mbar);
    JMenu fileMenu = new JMenu("File");
    JMenuItem connectItem = new JMenuItem("connect");
    connectItem.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        //if 1st time,construct a dialog
        passwordChooser = new PasswordChooser(LoginDemoStart.this);
        passwordChooser.setVisible(true);
        if(passwordChooser.isLogedIn())
        {
          User u = passwordChooser.getUser();
          textArea.append("Username = " + u.getName() + ", Password = " + new String(u.getPassword()) + "\n");
        }
      }
    });
    JMenuItem exitItem = new JMenuItem("exit");
    exitItem.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        System.exit(0);
      }
    });
    mbar.add(fileMenu);
    fileMenu.add(connectItem);
    fileMenu.add(exitItem);
    //添加文本区域
    textArea = new JTextArea();
    add(new JScrollPane(textArea), BorderLayout.CENTER);
    //设置窗体属性
    setTitle("LoginDemoStart - www.jb51.net");
    setSize(300,200);
    setLocationRelativeTo(null);
  }
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    LoginDemoStart loginDemoStart = new LoginDemoStart();
    loginDemoStart.setVisible(true);
  }
}

package awtDemo;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/*
 * @功能：提供登陆UI并获取用户信息
 * @版本：20150804
 */
@SuppressWarnings("serial")
class PasswordChooser extends JDialog{
  private JTextField username ;
  private JPasswordField password ;
  private JButton okButton ;
  private JButton cancelButton ;
  private boolean isLogedIn = false;
  public PasswordChooser(Frame parent){
    super(parent, true);
    //本UI包含2个panel
    JPanel inputPanel = new JPanel();
    JPanel buttonPanel = new JPanel();
    //构造inputPanel    
    inputPanel.setLayout(new GridLayout(2,2));
    inputPanel.add(new JLabel("Useername:"));
    username = new JTextField();
    username.setColumns(10);
    password = new JPasswordField();
    password.setColumns(10);
    inputPanel.add(username);
    inputPanel.add(new JLabel("Password:"));
    inputPanel.add(password);
    inputPanel.setBorder(BorderFactory.createEmptyBorder(10, 5, 10, 5));
    //构造buttonPanel    
    okButton = new JButton("OK");
    okButton.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        isLogedIn = true;
        setVisible(false);
      }
    });
    cancelButton = new JButton("Cancel");
    cancelButton.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        setVisible(false);
      }
    });
    buttonPanel.add(okButton);
    buttonPanel.add(cancelButton);
    buttonPanel.setBorder(BorderFactory.createEmptyBorder(10, 5, 10, 5));
    //构造主框架
    setLayout(new BorderLayout());
    getContentPane().add(inputPanel, BorderLayout.NORTH);
    getContentPane().add(buttonPanel, BorderLayout.SOUTH);
    //设置窗体属性
    setTitle("PasswordChooser - www.jb51.net");
    setLocationRelativeTo(inputPanel);
    //setPreferredSize(new Dimension(300, 200));
    pack();
    //System.out.println(getPreferredSize());
  }
  public void setUser(User u){
    username.setText(u.getName());
  }
  public User getUser(){
    return new User(username.getText(), password.getPassword());
  }    
  public boolean isLogedIn(){
    return isLogedIn;
  }    
  public static void main(String[] args) {
    // TODO Auto-generated method stub
  }
}

package awtDemo;
/*
 * @功能：保存用户信息
 * @版本：20150804
 */
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;
  }
}