文件拖放问题
很多软件都可以实现这样的功能:用鼠标将一堆文件拖到程序框里,然后对这些文件进行处理(比如打开之类的),谁知道用java的话怎么实现这样的效果(主要是取到这些文件的路径列表)
/** @version 1.02 2004-08-25 @author Cay Horstmann */ import java.awt.*; import java.awt.datatransfer.*; import java.awt.event.*; import java.awt.dnd.*; import *; import java.util.*; import javax.swing.*; /** This is a test class to test drag and drop behavior. Drop items into the text area to see the MIME types of the drop target. */ public class DropTargetTest { public static void main(String[] args) { JFrame frame = new DropTargetFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } } /** This frame contains a text area that is a simple drop target. */ class DropTargetFrame extends JFrame { public DropTargetFrame() { setTitle("DropTarget"); setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); JTextArea textArea = new JTextArea("Drop items into this text area.\n"); new DropTarget(textArea, new TextDropTargetListener(textArea)); add(new JScrollPane(textArea), "Center"); } private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 300; } /** This listener displays the properties of a dropped object. */ class TextDropTargetListener implements DropTargetListener { /** Constructs a listener. @param aTextArea the text area in which to display the properties of the dropped object. */ public TextDropTargetListener(JTextArea aTextArea) { textArea = aTextArea; } public void dragEnter(DropTargetDragEvent event) { int a = event.getDropAction(); if ((a & DnDConstants.ACTION_COPY) != 0) textArea.append("ACTION_COPY\n"); if ((a & DnDConstants.ACTION_MOVE) != 0) textArea.append("ACTION_MOVE\n"); if ((a & DnDConstants.ACTION_LINK) != 0) textArea.append("ACTION_LINK\n"); if (!isDragAcceptable(event)) { event.rejectDrag(); return; } } public void dragExit(DropTargetEvent event) { } public void dragOver(DropTargetDragEvent event) { // you can provide visual feedback here } public void dropActionChanged(DropTargetDragEvent event) { if (!isDragAcceptable(event)) { event.rejectDrag(); return; } } public void drop(DropTargetDropEvent event) { if (!isDropAcceptable(event)) { event.rejectDrop(); return; } event.acceptDrop(DnDConstants.ACTION_COPY); Transferable transferable = event.getTransferable(); DataFlavor[] flavors = transferable.getTransferDataFlavors(); for (int i = 0; i < flavors.length; i++) { DataFlavor d = flavors[i]; textArea.append("MIME type=" + d.getMimeType() + "\n"); try { if (d.equals(DataFlavor.javaFileListFlavor)) { java.util.List<File> fileList = (java.util.List<File>) transferable.getTransferData(d); for (File f : fileList) { textArea.append(f + "\n"); } } else if (d.equals(DataFlavor.stringFlavor)) { String s = (String) transferable.getTransferData(d); textArea.append(s + "\n"); } } catch (Exception e) { textArea.append(e + "\n"); } } textArea.append("\n"); event.dropComplete(true); } public boolean isDragAcceptable(DropTargetDragEvent event) { // usually, you check the available data flavors here // in this program, we accept all flavors return (event.getDropAction() & DnDConstants.ACTION_COPY_OR_MOVE) != 0; } public boolean isDropAcceptable(DropTargetDropEvent event) { // usually, you check the available data flavors here // in this program, we accept all flavors return (event.getDropAction() & DnDConstants.ACTION_COPY_OR_MOVE) != 0; } private JTextArea textArea; }