如何定期更新java swing / jFrame窗口中的标签？

Question

我目前正在尝试编写一个简单的程序，它将在BPM中以给定的间隔显示音符。我已经编写了大部分代码，但是我无法弄清楚如何获取包含注释和sharp / flat的标签来更新给定的每个间隔。到目前为止这是我的代码。 NoteGenerator对象是我自己创建的，仅用于生成随机音符/ sharp / flat并跟踪速度。我已经测试了NoteGenerator类，它的工作方式与我的预期完全相同。提前谢谢！

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JSpinner;
import javax.swing.JLabel;
import java.awt.Font;
import javax.swing.JButton;
import javax.swing.SpinnerNumberModel;
import javax.swing.Timer;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class NotePractice extends JFrame {

    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    NotePractice frame = new NotePractice();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public NotePractice() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);
        NoteGenerator noteGen = new NoteGenerator();

        JSpinner spinner = new JSpinner();
        spinner.setModel(new SpinnerNumberModel(new Integer(100), new Integer(20), null, new Integer(5)));
        spinner.setBounds(211, 196, 60, 20);
        contentPane.add(spinner);

        JLabel lblBpm = new JLabel("BPM");
        lblBpm.setFont(new Font("Arial", Font.BOLD, 12));
        lblBpm.setBounds(175, 198, 26, 14);
        contentPane.add(lblBpm);

        JLabel lblNote = new JLabel(noteGen.getNote());
        lblNote.setFont(new Font("Arial", Font.BOLD, 99));
        lblNote.setBounds(175, 60, 82, 104);
        contentPane.add(lblNote);

        JLabel lblStep = new JLabel(noteGen.getStep());
        lblStep.setFont(new Font("Arial", Font.BOLD, 70));
        lblStep.setBounds(258, 93, 60, 58);
        contentPane.add(lblStep);

        JButton btnUpdateTempo = new JButton("Update Tempo");
        btnUpdateTempo.setFont(new Font("Arial", Font.PLAIN, 11));
        btnUpdateTempo.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                noteGen.setBPM(spinner.getComponentCount());
                Timer t = new Timer(noteGen.getBPM(), new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        lblNote.setText(noteGen.getNote());
                        lblStep.setText(noteGen.getStep());
                        contentPane.updateUI();
                    }
                });
            }
        });
        btnUpdateTempo.setBounds(168, 227, 103, 23);
        contentPane.add(btnUpdateTempo);
    }
}