Java by API/java.awt.dnd/DropTargetListener

implements DropTargetListener

import java.awt.BorderLayout;
import java.awt.Color;
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.DragSourceContext;
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.dnd.InvalidDnDOperationException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class MainClass extends JFrame implements ActionListener, DropTargetListener {
  DragLabel source = new DragLabel("Drag and drop me to the following JButton", JLabel.CENTER);
  JButton target = new JButton();
  MainClass(String title) {
    super(title);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    source.setForeground(Color.red);
    getContentPane().add(source, BorderLayout.NORTH);
    target.addActionListener(this);
    getContentPane().add(target, BorderLayout.SOUTH);
    new DropTarget(target, DnDConstants.ACTION_COPY_OR_MOVE, this);
    setSize(205, 100);
    setVisible(true);
  }
  public void actionPerformed(ActionEvent e) {
    JButton b = (JButton) e.getSource();
    b.setText("");
    source.setText("Drag and drop me to the following JButton");
  }
  public void dragEnter(DropTargetDragEvent e) {
    System.out.println("Entering drop target #1");
  }
  public void dragExit(DropTargetEvent e) {
    System.out.println("Exiting drop target #1");
  }
  public void dragOver(DropTargetDragEvent e) {
    System.out.println("Dragging over drop target #1");
  }
  public void drop(DropTargetDropEvent e) {
    System.out.println("Dropping");
    try {
      Transferable t = e.getTransferable();
      if (e.isDataFlavorSupported(DataFlavor.stringFlavor)) {
        e.acceptDrop(e.getDropAction());
        String s;
        s = (String) t.getTransferData(DataFlavor.stringFlavor);
        target.setText(s);
        e.dropComplete(true);
      } else
        e.rejectDrop();
    } catch (java.io.IOException e2) {
    } catch (UnsupportedFlavorException e2) {
    }
  }
  public void dropActionChanged(DropTargetDragEvent e) {
    System.out.println("Drop action changed #1");
  }
  public static void main(String[] args) {
    new MainClass("Drag and Drop Demo");
  }
}
class DragLabel extends JLabel implements DragGestureListener, DragSourceListener {
  private DragSource ds = DragSource.getDefaultDragSource();
  public DragLabel(String s, int alignment) {
    super(s, alignment);
    int action = DnDConstants.ACTION_COPY_OR_MOVE;
    ds.createDefaultDragGestureRecognizer(this, action, this);
  }
  public void dragGestureRecognized(DragGestureEvent e) {
    try {
      Transferable t = new StringSelection(getText());
      e.startDrag(DragSource.DefaultCopyNoDrop, t, this);
    } catch (InvalidDnDOperationException e2) {
      System.out.println(e2);
    }
  }
  public void dragDropEnd(DragSourceDropEvent e) {
    System.out.println("Drag and drop end");
    if (e.getDropSuccess() == false) {
      System.out.println("unsuccessful");
      return;
    }
    int action = e.getDropAction();
    if ((action & DnDConstants.ACTION_MOVE) != 0)
      setText("");
  }
  public void dragEnter(DragSourceDragEvent e) {
    System.out.println("Entering drop target #2");
    DragSourceContext ctx = e.getDragSourceContext();
    int action = e.getDropAction();
    if ((action & DnDConstants.ACTION_COPY) != 0)
      ctx.setCursor(DragSource.DefaultCopyDrop);
    else
      ctx.setCursor(DragSource.DefaultCopyNoDrop);
  }
  public void dragExit(DragSourceEvent e) {
    System.out.println("Exiting drop target #2");
  }
  public void dragOver(DragSourceDragEvent e) {
    System.out.println("Dragging over drop target #2");
  }
  public void dropActionChanged(DragSourceDragEvent e) {
    System.out.println("Drop action changed #2");
  }
}

implements DropTargetListener (Get drop file from file explor)

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.DnDConstants;
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 javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextArea;
public class DropTest extends JFrame implements DropTargetListener {
  DropTarget dt;
  JTextArea ta = new JTextArea();
  public DropTest() {
    super("Drop Test");
    setSize(300, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    add(new JLabel("Drop a list from your file chooser here:"), BorderLayout.NORTH);
    ta.setBackground(Color.white);
    getContentPane().add(ta, BorderLayout.CENTER);
    dt = new DropTarget(ta, this);
    setVisible(true);
  }
  public void dragEnter(DropTargetDragEvent dtde) {
    System.out.println("Drag Enter");
  }
  public void dragExit(DropTargetEvent dte) {
    System.out.println("Source: " + dte.getSource());
    System.out.println("Drag Exit");
  }
  public void dragOver(DropTargetDragEvent dtde) {
    System.out.println("Drag Over");
  }
  public void dropActionChanged(DropTargetDragEvent dtde) {
    System.out.println("Drop Action Changed");
  }
  public void drop(DropTargetDropEvent dtde) {
    try {
      Transferable tr = dtde.getTransferable();
      DataFlavor[] flavors = tr.getTransferDataFlavors();
      for (int i = 0; i < flavors.length; i++) {
        System.out.println("Possible flavor: " + flavors[i].getMimeType());
        if (flavors[i].isFlavorJavaFileListType()) {
          dtde.acceptDrop(DnDConstants.ACTION_COPY);
          ta.setText("Successful file list drop.\n\n");
          java.util.List list = (java.util.List) tr.getTransferData(flavors[i]);
          for (int j = 0; j < list.size(); j++) {
            ta.append(list.get(j) + "\n");
          }
          dtde.dropComplete(true);
          return;
        }
      }
      System.out.println("Drop failed: " + dtde);
      dtde.rejectDrop();
    } catch (Exception e) {
      e.printStackTrace();
      dtde.rejectDrop();
    }
  }
  public static void main(String args[]) {
    new DropTest();
  }
}