Touchatag reader example

import java.io.*;
import java.util.*;
import javax.smartcardio.*;
import java.util.List;
import java.math.BigInteger;

public class Touchatag {
 private CardTerminal terminal;
  public Touchatag() throws CardException {
      CardTerminals terminals = TerminalFactory.getDefault().terminals();
      terminal = terminals.list().get(0);
  }
  public Touchatag(String readerName) {
      CardTerminals terminals = TerminalFactory.getDefault().terminals();
      terminal = terminals.getTerminal(readerName);
  }
  public byte[] getCardUID() throws CardException {
      Card card = terminal.connect("*");
      ResponseAPDU response = card.getBasicChannel().transmit(
              new CommandAPDU(new byte[] { (byte) 0xFF, 0x00, 0x00, 0x00,
                      0x04, (byte) 0xD4, 0x4A, 0x01, 0x00 }));
      card.disconnect(true);
      if (response.getSW1() == 0x90) {
          byte[] data = response.getData();
          data = Arrays.copyOfRange(data, 0x08, data.length);
          return data;
      }
      return new byte[] {};
  }
  public static void main(String[] args) throws CardException {
      Touchatag touchatag = new Touchatag();
      byte[] bytes = touchatag.getCardUID();
      System.out.println(String.format("%0" + (bytes.length << 1) + "X", new
BigInteger(1, bytes)));
  }
}