Java tutorial
import java.awt.BorderLayout; import java.util.Vector; import javax.swing.ImageIcon; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTree; import javax.swing.UIManager; class TreeNodeVector<E> extends Vector<E> { String name; TreeNodeVector(String name) { this.name = name; } TreeNodeVector(String name, E elements[]) { this.name = name; for (int i = 0, n = elements.length; i < n; i++) { add(elements[i]); } } public String toString() { return "[" + name + "]"; } } public class ChangingTreeOpenIcon { public static void main(final String args[]) { UIManager.put("Tree.openIcon", new ImageIcon("yourFile.gif")); JFrame frame = new JFrame("JTreeSample"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Vector<String> v1 = new TreeNodeVector<String>("Two", new String[] { "Mercury", "Venus", "Mars" }); Vector<Object> v2 = new TreeNodeVector<Object>("Three"); v2.add(System.getProperties()); v2.add(v1); Object rootNodes[] = { v1, v2 }; Vector<Object> rootVector = new TreeNodeVector<Object>("Root", rootNodes); JTree tree = new JTree(rootVector); frame.add(new JScrollPane(tree), BorderLayout.CENTER); frame.setSize(300, 300); frame.setVisible(true); } }