Java - 密码字段字符计数器

Question

我有一个作业问题，要求我创建一个 JPasswordField。需要两个按钮，一个用于在另一个文本字段中显示实际密码，另一个仅在文本字段中显示字符数。这是我到目前为止所要做的，但我无法编译它，因为Method setText in class javax.swing.text.JTextComponent cannot be applied to given types. 当我希望编译器自行读取密码时，编译器会在bt1 下停止。

谁能帮忙？

谢谢。 代码：

public class JavaPasswordCount {  
    public JavaPasswordCount() {
        JFrame window = new JFrame("Password Character Count");
        window.setSize(50, 50);
        JButton bt1 = new JButton("Show Count");
        JButton bt2 = new JButton("Show Password");
        final JPasswordField pwd = new JPasswordField();
        final JTextField tf = new JTextField(); 
        final int counter;

        JPanel panel = new JPanel(); 

        bt1.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                tf.setText(pwd.getPassword());
            }
        });

        bt2.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                counter = pwd.length();
                tf.setText(counter);
            }
        });

        panel.setLayout(new FlowLayout()); // Add buttons and TextField to the panel
        panel.add(tf);
        panel.add(pwd);
        panel.add(bt1);
        panel.add(bt2);

        window.getContentPane().add(panel, BorderLayout.CENTER);
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.pack();
        window.setVisible(true);
    }
    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
        } catch (Exception e) {
        }

        JavaPasswordCount application = new JavaPasswordCount();
    }
}

Answer 1

更改此行：

counter = pwd.length();
tf.setText(counter);

到

int counter = pwd.getPassword().length;
tf.setText(String.valueOf((counter)));

还有这个

tf.setText(pwd.getPassword());

到

tf.setText(pwd.getPassword().toString());