应用场景：用户注册，密码输入

功能界面：

193017785.jpg

窗口界面设计部分代码：

public class JPasswordFieldTest extends JFrame {
                      
    /**
     *
     */
    private static final long serialVersionUID = 8633179606754193326L;
    private JPanel contentPane;
    private JPasswordField passwordField1;
    private JPasswordField passwordField2;
                      
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (Throwable e) {
            e.printStackTrace();
        }
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    JPasswordFieldTest frame = new JPasswordFieldTest();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
                      
    /**
     * Create the frame.
     */
    public JPasswordFieldTest() {
        setTitle("\u5BC6\u7801\u57DF\u63A7\u4EF6\u7B80\u5355\u5E94\u7528");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 200);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(new GridLayout(3, 1, 5, 5));
                          
        JPanel passwordPanel1 = new JPanel();
        contentPane.add(passwordPanel1);
                          
        JLabel label1 = new JLabel("\u8F93\u5165\u5BC6\u7801\uFF1A");
        label1.setFont(new Font("微软雅黑", Font.PLAIN, 16));
        passwordPanel1.add(label1);
                          
        passwordField1 = new JPasswordField();
        passwordField1.setFont(new Font("微软雅黑", Font.PLAIN, 16));
        passwordField1.setColumns(20);
        passwordPanel1.add(passwordField1);
                          
        JPanel passwordPanel2 = new JPanel();
        contentPane.add(passwordPanel2);
                          
        JLabel label2 = new JLabel("\u786E\u8BA4\u5BC6\u7801\uFF1A");
        label2.setFont(new Font("微软雅黑", Font.PLAIN, 16));
        passwordPanel2.add(label2);
                          
        passwordField2 = new JPasswordField();
        passwordField2.setFont(new Font("微软雅黑", Font.PLAIN, 16));
        passwordField2.setColumns(20);
        passwordPanel2.add(passwordField2);
                          
        JPanel buttonPanel = new JPanel();
        contentPane.add(buttonPanel);
                          
        JButton submitButton = new JButton("\u63D0\u4EA4");
        submitButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                do_submitButton_actionPerformed(e);
            }
        });
        submitButton.setFont(new Font("微软雅黑", Font.PLAIN, 18));
        buttonPanel.add(submitButton);
    }


判断部分代码：

protected void do_submitButton_actionPerformed(ActionEvent e) {
       char[] password1 = passwordField1.getPassword();
       char[] password2 = passwordField2.getPassword();
       if (password1.length < 6) {
           JOptionPane.showMessageDialog(this, "密码长度小于6位", "", JOptionPane.WARNING_MESSAGE);
       } else if (!Arrays.equals(password1, password2)) {
           JOptionPane.showMessageDialog(this, "两次密码不同", "", JOptionPane.WARNING_MESSAGE);
       } else {
           JOptionPane.showMessageDialog(this, "两次密码相同", "", JOptionPane.INFORMATION_MESSAGE);
       }
   }