title: Java: remove margin / padding on a JTabbedPane
body: <p>I'd like to know how to remove the margins between my JtabbedPane and my JFrame content pane and between my JTabbedPane and its internal JPanel.
  I circled the margins I want to remove.
  the green line is here to show the gap between the jpanel inside the jtabbedpane.</p>
  
  <p>I tried to look at some method named <code>setMargin</code> but it doesn't exist on a JTabbedPane. I also checked the <code>Hgap</code> and <code>Vgap</code> (both = 0) on the different layout (root content pane, my jpanel, etc).</p>
  
  <p>So any suggestions are welcome.
  Thanks.</p>
  
  <p><img src="https://i.stack.imgur.com/DlD8J.png" alt="The image is here">.</p>
  
  <p>I can't post images yet.</p>