JRuby gives me the opportunity to find which is worse, my Swing or my Ruby

app.jruby

require 'java'
swing_classes = %w(JFrame JButton JList JSplitPane 
             JTabbedPane JTextPane JScrollPane JEditorPane 
             DefaultListModel ListSelectionModel BoxLayout
             JScrollPane JTree tree.TreeModel
             text.html.HTMLEditorKit tree.DefaultMutableTreeNode tree.TreeNode)
swing_classes.each do |c|
  java_import "javax.swing.#{c}"
end


def main 
  n = 0
  frame = JFrame.new("Disk File Info")
  dir = Dir.new("./testdir")
  dir_node = DefaultMutableTreeNode.new(dir)
  tree = JTree.new(dir_node)
  scrollPane = JScrollPane.new(tree)
  dir.each { |f|  
    node = DefaultMutableTreeNode.new(f)
    dir_node.insert(node, n)
    n += 1
  }
  cp = frame.getContentPane()
  cp.add(scrollPane)

  frame.setDefaultCloseOperation(JFrame::EXIT_ON_CLOSE)
  frame.pack()
  frame.set_visible(true)
end

main