MD5sumForm

import java.awt.Button;
import java.awt.Frame;
import java.awt.List;
import java.awt.Toolkit;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
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.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.security.MessageDigest;
public class MD5sumForm extends WindowAdapter implements ActionListener
{
 private static RecordList fileList = new MD5sumForm.RecordList();
 private static final String msg = "Drag file(s) here to get MD5";
 public static void main(String[] args)
 {
  Frame window = new Frame();
  window.setSize(400, 350);
  window.setLayout(null);
  window.setLocation(480, 320);
  window.setResizable(false);
  window.setTitle("MD5sum - By Wafly");
  window.add(fileList);
  final Button emptyBtn = new Button("Empty");
  emptyBtn.setSize(100, 20);
  emptyBtn.setLocation(280, 315);
  window.add(emptyBtn);
  MD5sumForm evi = new MD5sumForm();
  window.addWindowListener(evi);
  emptyBtn.addActionListener(evi);
    
  window.setVisible(true);
 }
 
 public void windowClosing(WindowEvent e)
 {
  System.exit(0);
 }
 
 public void actionPerformed(ActionEvent actionevent)
 {
  fileList.removeAll();
  fileList.add(msg);
 }
 private static void addFile(String filePath) {
  if (filePath == null || filePath.trim().length() == 0)
   return;
  if (new File(filePath).exists())
  {
   try {
    MessageDigest messagedigest = MessageDigest.getInstance("MD5");
    InputStream fis = new FileInputStream(filePath);
    byte[] buffer = new byte[1024];
    int numRead = 0;
    while ((numRead = fis.read(buffer)) > 0)
     messagedigest.update(buffer, 0, numRead);
    fis.close();
    byte bytes[] = messagedigest.digest();
    StringBuffer stringbuffer = new StringBuffer(2 * bytes.length);
    char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
    int k = bytes.length;
    for (int l = 0; l < k; l++)
    {
     stringbuffer.append(hexDigits[(bytes[l] & 0xf0) >> 4]);
     stringbuffer.append(hexDigits[bytes[l] & 0xf]);
    }
    fileList.add(stringbuffer + " - " + filePath);
   } catch (Exception e) {
    fileList.add("-------------------------------- - " + filePath);
   }
  }
 }
 private static class RecordList extends List implements DropTargetListener,KeyListener,ItemListener {
  private static final long serialVersionUID = 1L;
  private int lastSelectItemID = -1;
  
  public RecordList()
  {
   setSize(360, 250);
   setLocation(20, 50);
   setMultipleMode(true);
   new DropTarget(this, this);
   addKeyListener(this);
   addItemListener(this);
   add(msg);
  }
  private boolean isCTRLdown=false;
  private boolean isShiftDown=false;
  public void dragEnter(DropTargetDragEvent event) { }
  public void dragExit(DropTargetEvent event) { }
  public void dragOver(DropTargetDragEvent event) { }
  public void dropActionChanged(DropTargetDragEvent event) { }
  public void keyTyped(KeyEvent keyevent) { }
  public void drop(DropTargetDropEvent event)
  {
   if(getItemCount()>0 && msg.equals(getItem(0)))
    remove(0);
   event.acceptDrop(1);
   Transferable transferable = event.getTransferable();
   DataFlavor[] flavors = transferable.getTransferDataFlavors();
   for (int i = 0; i < flavors.length; i++)
   {
    DataFlavor d = flavors[i];
    try {
     if (d.equals(DataFlavor.javaFileListFlavor))
     {
      java.util.List fileList = (java.util.List) transferable.getTransferData(d);
      for (int j=0; j<fileList.size(); j++)
       addFile(((File)fileList.get(j)).getAbsolutePath());
     }
    } catch (Exception e) { }
   }
  }
  public void keyPressed(KeyEvent keyevent) {
   switch(keyevent.getKeyCode())
   {
   case KeyEvent.VK_CONTROL:
    isCTRLdown=true;
    break;
   case KeyEvent.VK_SHIFT:
    isShiftDown=true;
    break;
   case KeyEvent.VK_C:
    if(isCTRLdown)
    {
     StringBuffer icsb = new StringBuffer();
     String[] items = getSelectedItems();
     for(int i=0; i<items.length; i++)
      icsb.append(items[i]).append("\n");
     StringSelection stsel = new StringSelection(icsb.toString());
        Toolkit.getDefaultToolkit().getSystemClipboard().setContents(stsel, stsel);
    }
    break;
   case KeyEvent.VK_A:
    if(isCTRLdown)
    {
     for(int i=0; i<getItemCount(); i++)
      select(i);
    }
    break;
   case KeyEvent.VK_DELETE:
    int[] selectedIndexes = getSelectedIndexes();
    for(int i=selectedIndexes.length-1; i>=0; i--)
     remove(selectedIndexes[i]);
    if(getItemCount()==0)
     add(msg);
    break;
   }
  }
  public void keyReleased(KeyEvent keyevent) {
   switch(keyevent.getKeyCode())
   {
   case KeyEvent.VK_CONTROL:
    isCTRLdown=false;
    break;
   case KeyEvent.VK_SHIFT:
    isShiftDown=false;
    break;
   }
  }
  
  public void itemStateChanged(ItemEvent itemevent) {
   boolean hasOperation = false;
   int currID=Integer.parseInt(itemevent.getItem().toString());
   if(lastSelectItemID>-1 && isShiftDown)
   {
    for(int i=0; i<=getItemCount(); i++)
    {
     if((currID>lastSelectItemID && (i<lastSelectItemID || i>currID))
       || (currID<lastSelectItemID && (i>lastSelectItemID || i<currID)))
      deselect(i);
     else
      select(i);
    }
    hasOperation=true;
   }
   else if(isCTRLdown)
   {
    hasOperation=true;
    if(itemevent.getStateChange()==ItemEvent.SELECTED)
     lastSelectItemID=currID;
   }
   if(!hasOperation)
   {
    for(int i=0; i<getItemCount(); i++)
    {
     if(i==currID)
      select(i);
     else
      deselect(i);
    }
    lastSelectItemID=currID;
   }
  }
 }
}