《Java2图形设计卷II：Swing》配套光盘源码

				import javax.swing.*;
				import javax.swing.event.*;
				import javax.swing.tree.*;
				import java.awt.*;
				import java.awt.event.*;
				import java.io.File;
				import java.util.EventObject;
				
				public class Test extends JFrame {
					public Test() {
						JTree tree = new JTree(createTreeModel());
						JScrollPane scrollPane = new JScrollPane(tree);
				
						getContentPane().add(scrollPane, BorderLayout.CENTER);
						getContentPane().add(GJApp.getStatusArea(), 
														 BorderLayout.SOUTH);
				
						tree.getSelectionModel().setSelectionMode(
							TreeSelectionModel.SINGLE_TREE_SELECTION);
				
						tree.addTreeExpansionListener(new TreeExpansionListener(){
							public void treeCollapsed(TreeExpansionEvent e) {
							}
							public void treeExpanded(TreeExpansionEvent e) {
								UpdateStatus updateThread;
								TreePath path = e.getPath();
								FileNode node = (FileNode)
												   path.getLastPathComponent();
				
								if( ! node.isExplored()) {
									GJApp.updateStatus("exploring ...");
				
									UpdateStatus us = new UpdateStatus();
									us.start();
				
									node.explore();
								}
							}
							class UpdateStatus extends Thread {
								public void run() {
									try { Thread.currentThread().sleep(450); }
									catch(InterruptedException e) { }
				
									SwingUtilities.invokeLater(new Runnable() {
										public void run() {
											GJApp.updateStatus(" ");
										}
									});
								}
							}
						});
						tree.addTreeSelectionListener(
													new TreeSelectionListener() {
							public void valueChanged(TreeSelectionEvent e) {
								TreePath path = e.getNewLeadSelectionPath();
				
								if(path != null)
									GJApp.updateStatus("Path: " + path.toString());
							}
						});
					}
					private DefaultTreeModel createTreeModel() {
						File root = new File("E:/");
						FileNode rootNode = new FileNode(root), node;
				
						rootNode.explore();
						return new DefaultTreeModel(rootNode);
					}
					public static void main(String args[]) {
						GJApp.launch(new Test(),"TreePaths",300,300,450,400);
					}
				}
				class FileNode extends DefaultMutableTreeNode {
					private boolean explored = false;
				
					public FileNode(File file) 	{ 
						setUserObject(file); 
					}
					public boolean getAllowsChildren() { return isDirectory(); }
					public boolean isLeaf() 	{ return !isDirectory(); }
					public File getFile()		{ return (File)getUserObject(); }
				
					public void explore() 		{ explore(false); }
					public boolean isExplored() { return explored; }
				
					public boolean isDirectory() {
						File file = (File)getUserObject();
						return file.isDirectory();
					}
					public String toString() {
						File file = (File)getUserObject();
						String filename = file.toString();
						int index = filename.lastIndexOf("\\");
				
						return (index != -1 && index != filename.length()-1) ? 
													filename.substring(index+1) : 
													filename;
					}
					public void explore(boolean force) {
						if(!isExplored() || force) {
							File file = getFile();
							File[] children = file.listFiles();
				
							for(int i=0; i < children.length; ++i) 
								add(new FileNode(children[i]));
				
							explored = true;
						}
					}
				}
				class GJApp extends WindowAdapter {
					static private JPanel statusArea = new JPanel();
					static private JLabel status = new JLabel(" ");
				
					public static void launch(final JFrame f, String title,
											  final int x, final int y, 
											  final int w, int h) {
						f.setTitle(title);
						f.setBounds(x,y,w,h);
						f.setVisible(true);
				
						statusArea.setBorder(BorderFactory.createEtchedBorder());
						statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));
						statusArea.add(status);
						status.setHorizontalAlignment(JLabel.LEFT);
				
						f.setDefaultCloseOperation(
											WindowConstants.DISPOSE_ON_CLOSE);
				
						f.addWindowListener(new WindowAdapter() {
							public void windowClosed(WindowEvent e) {
								System.exit(0);
							}
						});
					}
					static public JPanel getStatusArea() {
						return statusArea;
					}
					static public void updateStatus(String s) {
						status.setText(s);
					}
				}