java swing的拖放例子

核心提示：我从java.sun.com和javaworld.com上的例子改过来的一棵文件系统树,支持拖放,CTRL+V复制文件import java.awt.AlphaComposite;import java.awt.Component;import java.awt.Graphics2D;import java.awt.P

　　我从java.sun.com和javaworld.com上的例子改过来的一棵文件系统树,支持拖放,CTRL+V复制文件

import java.awt.AlphaComposite;
import java.awt.Component;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DragGestureEvent;
import java.awt.dnd.DragGestureListener;
import java.awt.dnd.DragSource;
import java.awt.dnd.DragSourceDragEvent;
import java.awt.dnd.DragSourceDropEvent;
import java.awt.dnd.DragSourceEvent;
import java.awt.dnd.DragSourceListener;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.JTree;
import javax.swing.Timer;
import javax.swing.event.TreeEXPansionEvent;
import javax.swing.event.TreeExpansionListener;
import javax.swing.filechooser.FileSystemView;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;

class DragTree extends JTree implements DragGestureListener,
DragSourceListener, DropTargetListener {
BufferedImage GhostImage;

PRivate Rectangle2D ghostRect = new Rectangle2D.Float();

private Point ptOffset = new Point();

private Point lastPoint = new Point();

private TreePath lastPath;

private Timer hoverTimer;

FileNode sourceNode;

public DragTree() {
DragSource dragSource = DragSource.getDefaultDragSource();

dragSource.createDefaultDragGestureRecognizer(this, // component where