添加JLabel＆amp;时清空JFrame JTextField到它

Question

所以我应该创建一个非常简单的填充表单，如名称：______，它们应该在彼此之下，但是当我将这些JTextFields和JLabel添加到JFrame时，我得到一个空的JFrame。

JFrame frame = new JFrame("Name's Item Orders Calculator");

  JPanel panel = new JPanel();

  BorderLayout layout = new BorderLayout(0,2);

  JTextField nameField =  new JTextField(15);
  JTextField numberField = new JTextField(15);
  JTextField costField = new JTextField(15);
  JTextField amountField = new JTextField(15);

  JLabel name = new JLabel("Item Name: ");
  JLabel number = new JLabel("Number of: ");
  JLabel cost = new JLabel("Cost: ");
  JLabel amount = new JLabel("Amount owed: ");

  panel.add(name, BorderLayout.WEST);
  panel.add(number, BorderLayout.WEST);
  panel.add(cost, BorderLayout.WEST);
  panel.add(amount, BorderLayout.WEST);

  panel.add(nameField, BorderLayout.EAST);
  panel.add(numberField, BorderLayout.EAST);
  panel.add(costField, BorderLayout.EAST);
  panel.add(amountField, BorderLayout.EAST);

  /*
  panel.add(new JLabel("North"), BorderLayout.WEST);
  panel.add(new JLabel("Another North"), BorderLayout.WEST);
  */

  frame.pack();
  frame.add(panel);
  frame.setLayout(layout);
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.setSize(400, 200);
  frame.setLocationRelativeTo(null);
  frame.setVisible(true);