title: ScrollBar movement not smooth in JScrollpane in Swing
body: <p>I have a situation like this.
  I have scrollpane whose viewportView is a JPanel
  And that JPanel has the layout as BoxLayout. In this panel I add one class which extends JPanel and that class contains JComponents.</p>
  
  <p>So while running an application, the JComponents are shown in the JScrollPane.
  This is how my ScrollPane is formed.</p>
  
  <p>The problem here is, When the data exceeds more than around 750 rows, The scrollbar starts giving problems.
  When scrolling up or down by mouse wheel, scroll doesnot move smoothly, It suddenly stops in the middle and again starts, say it has a jerky movement.
  my Question is how can i get the smooth mouse movement in this scenario.</p>
  
  <p>My scrollPane is like this</p>
  
  <pre><code>public JScrollPane getScrollPane() {
      if (scrollPane == null) {
          scrollPane = new JScrollPane();
          scrollPane.setSize(new Dimension(1000, 433));
          scrollPane.setLocation(new Point(10, 10));
          scrollPane.setColumnHeaderView(getHeaderOfRowPanel());
          scrollPane
                  .setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
          scrollPane.setViewportView(getScrollPanel());
          scrollPane
                  .setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
          scrollPane.getVerticalScrollBar().setUnitIncrement(
                  unitIncrement);
  
      }
      return scrollPane;
  }
  
  private JPanel getScrollPanel() {
      if (scrollPanel == null) {
          scrollPanel = new JPanel();
          scrollPanel.setBorder(null);
          scrollPanel.setLayout(new BoxLayout(getScrollPanel(),
                  BoxLayout.Y_AXIS));
      }
      return scrollPanel;
  }
  
  
  private class RowPanel extends JPanel {
  //My components are here ..
  //I add this Panel in scrollPanel
  }
  </code></pre>