title: JButtons on GridLayout - MineSweeper
body: <p>I'm writing MineSweeper and using <code>JButton</code>s on a <code>GridLayout</code>. The numbers of rows and columns are entered by the user, so setting fixed size may cause several problems. </p>
  
  <p>How can I remove the space between the buttons without setting the fixed size of the panel?</p>
  
  <p><img src="https://i.stack.imgur.com/u6reJ.png" alt="Adjustable cell MineSweeper"></p>