title: Scrollbars not appearing in JScrollPane
body: <p>I want to make a window with two buttons with great heights and a scrollbar on a side. The problem is that no scrollbar appears. Here is my code</p>
  
  <pre><code>public class Window {
  
  /**
   * @param args
   */
  public static void main(String[] args) {
      // TODO Auto-generated method stub
  
      //namestanje teme
      try {
          UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
      } catch (ClassNotFoundException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
      } catch (InstantiationException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
      } catch (IllegalAccessException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
      } catch (UnsupportedLookAndFeelException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
      }
  
      JFrame frame = new JFrame("frame");
  //  frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
      frame.setSize(500,500);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  
      JPanel panel = new JPanel(null);
  
      JButton but1 = new JButton();
      JButton but2 = new JButton();
  
      panel.add(but1);
      panel.add(but2);
  
      but1.setSize(50, 505);
      but2.setSize(50, 505);
  
      but1.setLocation(0, 0);
      but2.setLocation(400, 400);
  
      but1.setText("1");
      but2.setText("2");
  
  
      JScrollPane scroll = new JScrollPane(panel);
  
      frame.add(scroll);
      frame.setVisible(true);         
  }
  }
  </code></pre>
  
  <p>Note: At first, the buttons had large widths (did that by naming them with something like "11111111111111111111111111111") and a scrollbar would appear. Then I wanted large heights and had to put null in panel. Now no scrollbar appears.</p>