import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;

public class FileTree
extends JFrame implements ActionListener
{
 
 public static final ImageIcon ICON_COMPUTER = new ImageIcon("computer.jpg");
  //new ImageIcon("computer.gif");
 public static final ImageIcon ICON_DISK = new ImageIcon("disk.gif");
  //new ImageIcon("disk.gif");
 public static final ImageIcon ICON_FOLDER =new ImageIcon("folder.gif");
  //new ImageIcon("folder.gif");
 public static final ImageIcon ICON_EXPANDEDFOLDER = new ImageIcon("folder.gif");
  //new ImageIcon("expandedfolder.gif");
      public static final ImageIcon ICON_File = new ImageIcon("file.gif");
  //new ImageIcon("expandedfolder.gif");

 protected JTree  m_tree;
 protected DefaultTreeModel m_model;
 protected JTextField m_display;
 protected JTextArea m_area;

 public FileTree()
 {
  super("文件管理器"); //构造JFrame 对象,初始化标题
  setSize(800, 600);//设置显示区域
              JMenuBar mBar = new JMenuBar();
                JMenu Menu1 = new JMenu("文件");
                JMenu Menu2 = new JMenu("编辑");
                JMenu Menu3 = new JMenu("查看");
                JMenu Menu4 = new JMenu("收藏");
                JMenu Menu5 = new JMenu("工具");
                JMenu Menu6 = new JMenu("帮助");
               //添加一级菜单
                mBar.add(Menu1);
                mBar.add(Menu2);
                mBar.add(Menu3);
                mBar.add(Menu4);
                mBar.add(Menu5);
                mBar.add(Menu6);
             
               //添加二级菜单
                JMenuItem m11=new JMenuItem("打开");
                JMenuItem m12=new JMenuItem("保存");
                JMenuItem m13=new JMenuItem("另存为");
                JMenuItem m14=new JMenuItem("新建");
                JMenuItem m15=new JMenuItem("退出");               
                JMenuItem m21=new JMenuItem("编辑");  
                JMenuItem m22=new JMenuItem("复制");  
                JMenuItem m23=new JMenuItem("粘贴");  
                JMenuItem m24=new JMenuItem("删除");
                JMenuItem m31=new JMenuItem("地址栏");
                JMenuItem m32=new JMenuItem("方式");
                JMenuItem m33=new JMenuItem("刷新");
                JMenuItem m41=new JMenuItem("添加到收藏夹");
                JMenuItem m51=new JMenuItem("文件夹选项");
                JMenuItem m61=new JMenuItem("关于主题");
                JMenuItem m62=new JMenuItem("作者信息");
                m11.addActionListener(this);
                m12.addActionListener(this);
                m13.addActionListener(this);
                m14.addActionListener(this);
                m15.addActionListener(this);
                m21.addActionListener(this);
                m22.addActionListener(this);
                m23.addActionListener(this);
                m24.addActionListener(this);
                m31.addActionListener(this);
                m32.addActionListener(this);
                m33.addActionListener(this);
                Menu1.add(m11);
                Menu1.add(m12);
                Menu1.add(m13);
                Menu1.add(m14);
                Menu1.add(m15);
                Menu2.add(m21);
                Menu2.add(m22);
                Menu2.add(m23);
                Menu2.add(m24);
                Menu3.add(m31);
                Menu3.add(m32);
                Menu3.add(m33);
                Menu4.add(m41);
                Menu5.add(m51);
                Menu6.add(m61);
                Menu6.add(m62);                          
                //显示工具栏
                JToolBar toolBar=new JToolBar("tool");
                toolBar.setVisible(true);                                                  
                JButton btPre=new JButton("前进");
                JButton btBack=new JButton("后退");
                JButton btUp=new JButton("向上");
                JButton btFiles=new JButton("文件夹");
                JButton btSrarch=new JButton("搜索");
                toolBar.add(btPre);
                toolBar.add(btBack);
                toolBar.add(btUp);
                toolBar.add(btFiles);
                toolBar.add(btSrarch);
                setJMenuBar(mBar); //- 设置放置于该窗体中的菜单栏
                this.getContentPane().add(toolBar,BorderLayout.NORTH);       
                toolBar.setFloatable(true);            
                this.setVisible(true);           
     //- 设置放置于该窗体中的菜单栏

  DefaultMutableTreeNode top = new DefaultMutableTreeNode(
    new IconData(ICON_COMPUTER, null, "我的电脑"));

//构造默认树形父节点,名字为Computer 

  DefaultMutableTreeNode node;
  File[] roots = File.listRoots();//列出可用的文件系统根。
  for (int k=0; k<roots.length; k++)
  {
   node = new DefaultMutableTreeNode(new IconData(ICON_DISK,
     null, new FileNode(roots[k])));
   top.add(node);//在树形父节点下构造其孩子节点
   node.add( new DefaultMutableTreeNode(new Boolean(true)));//在构造的孩子节点下构造字节点
  }

  m_model = new DefaultTreeModel(top);
  m_tree = new JTree(m_model);

  m_tree.putClientProperty("JTree.lineStyle", "Angled");

  TreeCellRenderer renderer = new
  IconCellRenderer();
  m_tree.setCellRenderer(renderer);

  m_tree.addTreeExpansionListener(new
    DirExpansionListener());

  m_tree.addTreeSelectionListener(new
    DirSelectionListener());

  m_tree.getSelectionModel().setSelectionMode(
    TreeSelectionModel.SINGLE_TREE_SELECTION);
  m_tree.setShowsRootHandles(true);
  m_tree.setEditable(false);
  

  
  JScrollPane s = new JScrollPane();
  s.getViewport().add(m_tree);
 // jp.add(s);

  m_area = new JTextArea();
  m_area.setEditable(false);
  
  JScrollPane sarea = new JScrollPane();
  sarea.getViewport().add(m_area);
 // jp.add(sarea);
  
  JSplitPane jp = new JSplitPane (JSplitPane.HORIZONTAL_SPLIT,true,s,sarea);
  getContentPane().add(jp,BorderLayout.CENTER);  
  
  m_display = new JTextField();
  m_display.setEditable(false);
  getContentPane().add(m_display, BorderLayout.SOUTH);

  WindowListener wndCloser = new WindowAdapter()
  {
   public void windowClosing(WindowEvent e)
   {
    System.exit(0);
   }
  };
  addWindowListener(wndCloser);

  setVisible(true);
 }

      public void actionPerformed(ActionEvent e)
        {
            if   (e.getActionCommand().equals("退出") )   System.exit(0);
        }

 DefaultMutableTreeNode getTreeNode(TreePath path)
 {
  return (DefaultMutableTreeNode)(path.getLastPathComponent());
 }

 FileNode getFileNode(DefaultMutableTreeNode node)
 {
  if (node == null)
   return null;
  Object obj = node.getUserObject();
  if (obj instanceof IconData)
   obj = ((IconData)obj).getObject();
  if (obj instanceof FileNode)
   return (FileNode)obj;
  else
   return null;
 }

 // Make sure expansion is threaded and updating the tree model
 // only occurs within the event dispatching thread.
 class DirExpansionListener implements TreeExpansionListener
 {
  public void treeExpanded(TreeExpansionEvent event)
  {
   final DefaultMutableTreeNode node = getTreeNode(
     event.getPath());
   final FileNode fnode = getFileNode(node);

   Thread runner = new Thread()
   {
    public void run()
    {
     if (fnode != null && fnode.expand(node))
     {
      Runnable runnable = new Runnable()
      {
       public void run()
       {
        m_model.reload(node);
       }
      };
      SwingUtilities.invokeLater(runnable);
     }
    }
   };
   runner.start();
  }

  public void treeCollapsed(TreeExpansionEvent event) {}
 }

 class DirSelectionListener
 implements TreeSelectionListener
 {
  public void valueChanged(TreeSelectionEvent event)
  {
   DefaultMutableTreeNode node = getTreeNode(
     event.getPath());
   FileNode fnode = getFileNode(node);
   if (fnode != null){
    m_display.setText(fnode.getFile().
      getAbsolutePath());
    
    File f = fnode.getFile();
    if(f.isFile() && f.getName().endsWith(".java")|| f.getName().endsWith(".txt") || f.getName().endsWith(".conf") ){
     try{
      BufferedReader in = new BufferedReader(new FileReader(f.getAbsoluteFile()));
      String line ;
      m_area.setText("");
      while( (line = in.readLine()) != null){
       m_area.append(line);
       m_area.append("\n");
       m_area.setEditable(true);
      }
     }catch(IOException e){
      e.printStackTrace();
     }
    }else{
     m_area.setText(f.toString()+f.lastModified()+f.length());
     m_area.setEditable(false);
    }
   }
   else{
    m_display.setText("");
    
   }
  }
 }

 public static void main(String argv[])
 {
  new FileTree();
 }
}

class IconCellRenderer
extends    JLabel
implements TreeCellRenderer
{
 protected Color m_textSelectionColor;
 protected Color m_textNonSelectionColor;
 protected Color m_bkSelectionColor;
 protected Color m_bkNonSelectionColor;
 protected Color m_borderSelectionColor;

 protected boolean m_selected;

 public IconCellRenderer()
 {
  super();
  m_textSelectionColor = UIManager.getColor(
  "Tree.selectionForeground");
  m_textNonSelectionColor = UIManager.getColor(
  "Tree.textForeground");
  m_bkSelectionColor = UIManager.getColor(
  "Tree.selectionBackground");
  m_bkNonSelectionColor = UIManager.getColor(
  "Tree.textBackground");
  m_borderSelectionColor = UIManager.getColor(
  "Tree.selectionBorderColor");
  setOpaque(false);
 }

 public Component getTreeCellRendererComponent(JTree tree,
   Object value, boolean sel, boolean expanded, boolean leaf,
   int row, boolean hasFocus)

 {
  DefaultMutableTreeNode node =
   (DefaultMutableTreeNode)value;
  Object obj = node.getUserObject();
  setText(obj.toString());

  if (obj instanceof Boolean)
   setText("Retrieving data...");

  if (obj instanceof IconData)
  {
   IconData idata = (IconData)obj;
   if (expanded)
    setIcon(idata.getExpandedIcon());
   else
    setIcon(idata.getIcon());
  }
  else
   setIcon(null);

  setFont(tree.getFont());
  setForeground(sel ? m_textSelectionColor :
   m_textNonSelectionColor);
  setBackground(sel ? m_bkSelectionColor :
   m_bkNonSelectionColor);
  m_selected = sel;
  return this;
 }

 public void paintComponent(Graphics g)
 {
  Color bColor = getBackground();
  Icon icon = getIcon();

  g.setColor(bColor);
  int offset = 0;
  if(icon != null && getText() != null)
   offset = (icon.getIconWidth() + getIconTextGap());
  g.fillRect(offset, 0, getWidth() - 1 - offset,
    getHeight() - 1);

  if (m_selected)
  {
   g.setColor(m_borderSelectionColor);
   g.drawRect(offset, 0, getWidth()-1-offset, getHeight()-1);
  }
  super.paintComponent(g);
 }
}

class IconData
{
 protected Icon   m_icon;
 protected Icon   m_expandedIcon;
 protected Object m_data;

 public IconData(Icon icon, Object data)
 {
  m_icon = icon;
  m_expandedIcon = null;
  m_data = data;
 }

 public IconData(Icon icon, Icon expandedIcon, Object data)
 {
  m_icon = icon;
  m_expandedIcon = expandedIcon;
  m_data = data;
 }

 public Icon getIcon()
 {
  return m_icon;
 }

 public Icon getExpandedIcon()
 {
  return m_expandedIcon!=null ? m_expandedIcon : m_icon;
 }

 public Object getObject()
 {
  return m_data;
 }

 public String toString()
 {
  return m_data.toString();
 }
}

class FileNode
{
 protected File m_file;

 public FileNode(File file)  //用文件类构造对象 java.io.File
 {
  m_file = file;
 }
    
 public File getFile() //返回文件对象
 {
  return m_file;
 }

 public String toString()
 {                               //getName()返回由此抽象路径名表示的文件或目录的名称
  return m_file.getName().length() > 0 ? m_file.getName() :
   m_file.getPath(); //getPath()将此抽象路径名转换为一个路径名字符串。
 }

 public boolean expand(DefaultMutableTreeNode parent)                                                           //javax.swing.tree.DefaultMutableTreeNode
 {
  DefaultMutableTreeNode flag =
  (DefaultMutableTreeNode)parent.getFirstChild();//返回此节点的第一个子节点
  if (flag==null)   // No flag
   return false;
  Object obj = flag.getUserObject(); //返回此节点的用户对象
  if (!(obj instanceof Boolean))
   return false;      // Already expanded

  parent.removeAllChildren();  // Remove Flag

  File[] files = listFiles(); //返回一个抽象路径名数组如果抽象路径名不表示一个                                               //目录则返回 null
  if (files == null)
   return true;

  Vector v = new Vector();

  for (int k=0; k<files.length; k++)
  {
   File f = files[k];
   //if (!(f.isDirectory()))
    //continue;

   FileNode newNode = new FileNode(f);

   boolean isAdded = false;
   for (int i=0; i<v.size(); i++)
   {
          FileNode nd = (FileNode)v.elementAt(i);
                             // Enumeration e=v.elementAt(i);
                             // FileNode nd=(FileNode)e;          //返回指定索引处的组件
    if (newNode.compareTo(nd) < 0)
    {
     v.insertElementAt(nd, i);
     isAdded = true;
     break;
    }
   }
   if (!isAdded)
    v.addElement(newNode);
  }

  for (int i=0; i<v.size(); i++)
  {     IconData idata;
     FileNode fnd = (FileNode)v.elementAt(i);
   if (fnd.hasSubDirs())
       idata = new IconData(FileTree.ICON_FOLDER,
        FileTree.ICON_EXPANDEDFOLDER, fnd);
                         else
                       idata = new IconData(FileTree.ICON_File,
         fnd);  
   DefaultMutableTreeNode node = new
   DefaultMutableTreeNode(idata);
   parent.add(node);

   if (fnd.hasSubDirs())
    node.add(new DefaultMutableTreeNode(
      new Boolean(true) ));
  }

  return true;
 }

 public boolean hasSubDirs()  //判断是否有子目录
 {
  File[] files = listFiles();
  if (files == null)
   return false;
  else
    return true;
  
  
 } //hasSubDirs()

 public int compareTo(FileNode toCompare)
 {
  return  m_file.getName().compareToIgnoreCase(toCompare.m_file.getName() );
 }//

 protected File[] listFiles()
 {
  if (!m_file.isDirectory())
   return null;
  try
  {
   return m_file.listFiles();
  }
  catch (Exception ex)
  {
   JOptionPane.showMessageDialog(null,
     "Error reading directory "+m_file.getAbsolutePath(),
     "Warning", JOptionPane.WARNING_MESSAGE);
   return null;
  }
 }
}

//July/整理/05.24/。