Drag and Drop a file in swing applications

Question

Hello friends,
is there anyway that i can know in my program that a file is dragged an dropped?
to be very clear, i want to allow a user to drag and drop a .txt file in my JFrame.
1. how do i know that user has dropped such file.
2. how can i restrict him to drop other files?
thanks in advance

Answer 1

Here is a code segment illustrating the method for obtaining the filename or path:
public void drop(final DropTargetDropEvent event)  {
          if ((event.getSourceActions() & DnDConstants.ACTION_COPY) != 0)
              event.acceptDrop(DnDConstants.ACTION_COPY);
         else {
             event.rejectDrop();
             return;
          Transferable transferable = event.getTransferable();
          DataFlavor[] flavors = event.getCurrentDataFlavors();
          for (int i = 0; i < flavors.length; i++)   {
               DataFlavor dataFlavor = flavors;
               try {
                    if (dataFlavor.equals(DataFlavor.javaFileListFlavor)) {
                         java.util.List fileList = (java.util.List) transferable.getTransferData(dataFlavor);
                         final File f = (File) fileList.get(0);
                         waiting = true;
                         Thread runner = new Thread() {
                              public void run() {                                                                  
                                   if (frame.promptToSave()) {
                                        frame.openDocument(f);     
                                   waiting = false;
                         runner.start();
                         event.dropComplete(true);
                         return;               
                    else if (dataFlavor.equals(DataFlavor.stringFlavor)) {               
                    textArea.setCaretPosition(textArea.viewToModel(event.getLocation()));
                    String s = (String) transferable.getTransferData(dataFlavor);
                    textArea.insert(s, textArea.getCaretPosition());
                    event.dropComplete(true);
                         return;          
//                    else if (d.isMimeTypeEqual("text/plain")) {               
               } catch (Exception e) {
                    event.dropComplete(false);
                    return;
          event.dropComplete(false);