Java GUI compiles with no errors, but sometimes shows nothing

Question

I'm using a custom class that extends JFrame, but sometimes it shows nothing. I never get any faults, so I'm curious if the is a java command that can help me print something. I looked around for other questions, but found nothing similar. Not really doing anything too crazy, but curious as to why this happens. I would like to correct the problem to avoid future problems.

Blank

GUI

public MemberPanel(int i) throws IOException {
  Container contentPane = getContentPane();
  GridLayout layout = new GridLayout(2, 1);
  contentPane.setLayout(layout);
  setVisible(true);
  setLocation(0, 0);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  setSize(640, 170);
  setResizable(false);

  greenStatus = new JButton("Non-Critical");
  yellowStatus = new JButton("Important");
  redStatus = new JButton("Mission Critical");

  greenStatus.setFont(fontTextOne);
  yellowStatus.setFont(fontTextOne);
  redStatus.setFont(fontTextOne);

  greenStatus.addActionListener(this);
  yellowStatus.addActionListener(this);
  redStatus.addActionListener(this);

  buttonPanel.add(greenStatus);
  buttonPanel.add(yellowStatus);
  buttonPanel.add(redStatus);

  statusLabel = new JLabel("In 75 letters or less... What are you working on?");
  statusLabel.setVerticalAlignment(JLabel.CENTER);
  statusLabel.setHorizontalAlignment(JLabel.CENTER);
  statusLabel.setFont(fontTextTwo);
  textFieldPanel.add(statusLabel);
  textFieldPanel.add(statusMessage);

  contentPane.add(buttonPanel);
  contentPane.add(textFieldPanel);

} 

Answer 1

You're adding a bunch of components after calling setVisible(true) on the JFrame:

public MemberPanel(int i) throws IOException {
  Container contentPane = getContentPane();
  GridLayout layout = new GridLayout(2, 1);
  contentPane.setLayout(layout);
  setVisible(true);  // ****** here

  // .....

  // only now do you add components...
  contentPane.add(buttonPanel);
  contentPane.add(textFieldPanel);

} 

And so the components may or may not show depending on whether the GUI repaints or not (see what happens when you re-size the empty gui). Fix: call setVisible(true) only after adding everything.