鼠标拖文件时获取文件路径（java）

今天药忘吃喽~ 2024-02-18 14:38 12阅读 0赞

此代码不是我写的，是Cay Horstmann写的，呵呵

/**
       @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 java.io.*;
    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;
    }