Java tutorial
import java.awt.BorderLayout; import javax.swing.Box; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTree; public class MainClass { public static void main(String args[]) { JFrame frame = new JFrame("Tree Lines"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Box box = Box.createHorizontalBox(); JTree tree1 = new JTree(); JScrollPane scrollPane1 = new JScrollPane(tree1); tree1.setAutoscrolls(true); JTree tree2 = new JTree(); tree2.putClientProperty("JTree.lineStyle", "None"); JScrollPane scrollPane2 = new JScrollPane(tree2); box.add(scrollPane1, BorderLayout.WEST); box.add(scrollPane2, BorderLayout.EAST); frame.add(box, BorderLayout.CENTER); frame.setSize(300, 240); frame.setVisible(true); } }