使jLabel成为可以打开文件的链接

Question

我试图将具有我计算机上文件路径文本的jLabel变为可以按下并使用方法的“链接”

java.awt.Desktop.getDesktop（）。open（selectedFile）;

当我按下它时，出现异常“线程“ AWT-EventQueue-0”中的异常java.lang.NullPointerException”

按jLabel的名称是“标签”。

我该如何解决？

  button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            JFileChooser file = new JFileChooser();
            file.setCurrentDirectory(new 
File(System.getProperty("user.home")));
            FileNameExtensionFilter filter = new 
FileNameExtensionFilter("*.Images", "jpg", "gif", "png");
            file.addChoosableFileFilter(filter);
            int result = file.showSaveDialog(null);

            if (result == JFileChooser.APPROVE_OPTION) {
                File selectedFile = file.getSelectedFile();
                String path = selectedFile.getAbsolutePath();
                label.setText(path);

            }

        }
    });

    class ButtonHandler implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            if (e.getSource() == emailknapp) {
                String message = showMessage.getText();

                String user = "mail@infbook.page";
                String pass = "Infbook2019";

                SendMail.send(email, "SupportChat conversation", message, 
user, pass);

            }
        }
    }

    label.addMouseListener(new MouseListener() {
        @Override
        public void mouseReleased(MouseEvent e) {

        }

        @Override
        public void mousePressed(MouseEvent e) {
        }

        @Override
        public void mouseExited(MouseEvent e) {
        }

        @Override
        public void mouseEntered(MouseEvent e) {
        }

        @Override
        public void mouseClicked(MouseEvent e) {
            try {
                java.awt.Desktop.getDesktop().open(selectedFile);
            } catch (IOException ex) {

Logger.getLogger(CustomerWindow.class.getName()).log(Level.SEVERE, null, 
ex);
            }

        }
    });