Logran crear una aplicación para cargar tarjeta bip!

// Decompiled by Jad v1.5.8e. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.geocities.com/kpdus/jad.html
// Decompiler options: braces fieldsfirst space lnc

package com.example.puntobip;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.MifareClassic;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import java.io.IOException;
import java.util.Random;

// Referenced classes of package com.example.puntobip:
//  TapDialog

public class MainActivity extends Activity
{

  private final byte DATA_CARGA_B21[];
  private final byte DATA_CARGA_B22[];
  private final int DIALOG_CARGAR = 2;
  private final int DIALOG_NUMERO = 3;
  private final int DIALOG_SALDO = 1;
  private final byte KEY_B_SECTOR_0[] = {
  31, -62, 53, -84, 19, 9
  };
  private final byte KEY_B_SECTOR_8[] = {
  100, -29, -63, 3, -108, -62
  };
  private IntentFilter mFilters[];
  private NfcAdapter mNfcAdapter;
  private PendingIntent mPendingIntent;
  private String mTechList[][];
  private TapDialog tapDialog;

  public MainActivity()
  {
  byte abyte0[] = new byte[16];
  abyte0[0] = 16;
  abyte0[1] = 39;
  abyte0[4] = -17;
  abyte0[5] = -40;
  abyte0[6] = -1;
  abyte0[7] = -1;
  abyte0[8] = 16;
  abyte0[9] = 39;
  abyte0[12] = 33;
  abyte0[13] = -34;
  abyte0[14] = 33;
  abyte0[15] = -34;
  DATA_CARGA_B21 = abyte0;
  byte abyte1[] = new byte[16];
  abyte1[0] = 16;
  abyte1[1] = 39;
  abyte1[4] = -17;
  abyte1[5] = -40;
  abyte1[6] = -1;
  abyte1[7] = -1;
  abyte1[8] = 16;
  abyte1[9] = 39;
  abyte1[12] = 34;
  abyte1[13] = -35;
  abyte1[14] = 34;
  abyte1[15] = -35;
  DATA_CARGA_B22 = abyte1;
  }

  private String formatMoneda(long l)
  {
  StringBuilder stringbuilder = new StringBuilder("$");
  Object aobj[] = new Object[1];
  aobj[0] = Long.valueOf(l);
  return stringbuilder.append(String.format("%,d", aobj)).toString();
  }

  private void inicializarNFC()
  {
  mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
  if (mNfcAdapter == null)
  {
  Toast.makeText(this, "Este dispositivo no soporta NFC.", 1).show();
  finish();
  return;
  }
  if (!mNfcAdapter.isEnabled())
  {
  AlertDialog alertdialog = (new android.app.AlertDialog.Builder(this)).create();
  alertdialog.setTitle("NFC deshabilitado");
  alertdialog.setMessage("Su NFC est\341 deshabilitado.\nIngrese a las opciones de configuraci\363n y activelo.");
  alertdialog.show();
  }
  mPendingIntent = PendingIntent.getActivity(this, 0, (new Intent(this, getClass())).addFlags(0x20000000), 0);
  IntentFilter intentfilter = new IntentFilter("android.nfc.action.TECH_DISCOVERED");
  String as[][];
  String as1[];
  try
  {
  intentfilter.addDataType("*/*");
  }
  catch (android.content.IntentFilter.MalformedMimeTypeException malformedmimetypeexception)
  {
  throw new RuntimeException("error", malformedmimetypeexception);
  }
  mFilters = (new IntentFilter[] {
  intentfilter
  });
  as = new String[1][];
  as1 = new String[1];
  as1[0] = android/nfc/tech/MifareClassic.getName();
  as[0] = as1;
  mTechList = as;
  }

  private long leToNumeric(byte abyte0[], int i)
  {
  long l = 0L;
  int j = 0;
  do
  {
  if (j >= i)
  {
  return l;
  }
  l += (255L & (long)abyte0[j]) << j * 8;
  j++;
  } while (true);
  }

  private String leToNumericString(byte abyte0[], int i)
  {
  return String.valueOf(leToNumeric(abyte0, i));
  }

  private void showTapDialog(String s, int i)
  {
  if (tapDialog == null)
  {
  tapDialog = new TapDialog(this);
  tapDialog.setCanceledOnTouchOutside(false);
  }
  tapDialog.setTitle(s);
  tapDialog.setTag(i);
  tapDialog.show();
  }

  public void onCambiarNumero(View view)
  {
  showTapDialog(getResources().getString(0x7f0a0010), 3);
  }

  public void onCargarSaldo(View view)
  {
  showTapDialog(getResources().getString(0x7f0a000f), 2);
  }

  protected void onCreate(Bundle bundle)
  {
  super.onCreate(bundle);
  setContentView(0x7f030018);
  showTapDialog(getResources().getString(0x7f0a000e), 1);
  inicializarNFC();
  }

  protected void onNewIntent(Intent intent)
  {
  if (!"android.nfc.action.TECH_DISCOVERED".equals(intent.getAction())) goto _L2; else goto _L1
_L1:
  MifareClassic mifareclassic = MifareClassic.get((Tag)intent.getParcelableExtra("android.nfc.extra.TAG"));
  mifareclassic.connect();
  if (!tapDialog.isShowing()) goto _L4; else goto _L3
_L3:
  tapDialog.getTag();
  JVM INSTR tableswitch 2 3: default 68
  //  2 236
  //  3 331;
  goto _L4 _L5 _L6
_L4:
  TextView textview1;
  TextView textview2;
  TextView textview = (TextView)findViewById(0x7f05003d);
  textview1 = (TextView)findViewById(0x7f05003e);
  textview2 = (TextView)findViewById(0x7f05003f);
  textview.setText(leToNumericString(mifareclassic.getTag().getId(), 4));
  if (!mifareclassic.authenticateSectorWithKeyB(0, KEY_B_SECTOR_0)) goto _L8; else goto _L7
_L7:
  byte abyte0[] = mifareclassic.readBlock(1);
  byte abyte1[] = new byte[4];
  abyte1[0] = abyte0[4];
  abyte1[1] = abyte0[5];
  abyte1[2] = abyte0[6];
  abyte1[3] = abyte0[7];
  textview1.setText(leToNumericString(abyte1, 4));
_L9:
  if (!mifareclassic.authenticateSectorWithKeyB(8, KEY_B_SECTOR_8))
  {
  break MISSING_BLOCK_LABEL_459;
  }
  textview2.setText(formatMoneda(leToNumeric(mifareclassic.readBlock(33), 2)));
_L10:
  Exception exception;
  Exception exception1;
  try
  {
  mifareclassic.close();
  }
  catch (IOException ioexception2) { }
_L2:
  tapDialog.dismiss();
  return;
_L5:
  if (!mifareclassic.authenticateSectorWithKeyB(8, KEY_B_SECTOR_8))
  {
  break MISSING_BLOCK_LABEL_310;
  }
  mifareclassic.writeBlock(33, DATA_CARGA_B21);
  mifareclassic.writeBlock(34, DATA_CARGA_B22);
  goto _L4
  exception1;
  Log.e("error", exception1.getLocalizedMessage());
  Toast.makeText(this, exception1.getLocalizedMessage(), 1).show();
  try
  {
  mifareclassic.close();
  }
  catch (IOException ioexception1) { }
  goto _L2
  Toast.makeText(this, "error autenticando sector 0x21", 1).show();
  goto _L4
  exception;
  byte abyte2[];
  Random random;
  try
  {
  mifareclassic.close();
  }
  catch (IOException ioexception) { }
  throw exception;
_L6:
label0:
  {
  if (!mifareclassic.authenticateSectorWithKeyB(0, KEY_B_SECTOR_0))
  {
  break label0;
  }
  abyte2 = mifareclassic.readBlock(1);
  random = new Random();
  abyte2[4] = (byte)(0 + random.nextInt(256));
  abyte2[5] = (byte)(0 + random.nextInt(256));
  abyte2[6] = (byte)(0 + random.nextInt(256));
  abyte2[7] = (byte)(0 + random.nextInt(256));
  mifareclassic.writeBlock(1, abyte2);
  }
  goto _L4
  Toast.makeText(this, "error autenticando sector 0x00", 1).show();
  goto _L4
_L8:
  Toast.makeText(this, "error autenticando sector 0x00", 1).show();
  goto _L9
  Toast.makeText(this, "error autenticando sector 0x21", 1).show();
  goto _L10
  }

  protected void onPause()
  {
  super.onPause();
  mNfcAdapter.disableForegroundDispatch(this);
  }

  protected void onResume()
  {
  super.onResume();
  mNfcAdapter.enableForegroundDispatch(this, mPendingIntent, mFilters, mTechList);
  }
}