title: Android NFC Coupon application terminated unexpectedly
body: <p>Thanks to the replies on NFC and a few certain things, I've understood and managed to compile a code in which the users will be able to read a tag, and if the tag contains a string that is similar to my code, a coupon will be added (image changes) and an integer goes up by 1. This integer will be saved by SharedPreferences and it is used to determine how many coupons the users have collected and show it onResume.</p>
  
  <p>However, after compiling, when I try to run it, my application stops immediately. Can someone help me check on what I may have go wrong? I know it's kinda long but I really have no idea what went wrong.</p>
  
  <pre><code>@TargetApi(10)    
  //I have to use this line of code because I'm targetted to code at API 8 but some NFC functionalities that I use requires API 10.
  
  public class CouponManager extends Activity {
  
          private static final String TAG = "NFCReadTag";
          private NfcAdapter mNfcAdapter;
          private IntentFilter[] mNdefExchangeFilters;
          private PendingIntent mNfcPendingIntent;
          public static final String PREF_FILE_NAME = "PrefFile";
  
          private int[] images = new int[10];
  
          @Override
          public void onCreate(Bundle savedInstanceState) {
              super.onCreate(savedInstanceState);
              setContentView(R.layout.coupon_layout);
  
              //List of images
              images[0]=R.drawable.cp0;
              images[1]=R.drawable.cp1;
              images[2]=R.drawable.cp2;
              images[3]=R.drawable.cp3;
              images[4]=R.drawable.cp4;
              images[5]=R.drawable.cp5;
              images[6]=R.drawable.cp6;
              images[7]=R.drawable.cp7;
              images[8]=R.drawable.cp8;
              images[9]=R.drawable.cp9;
              images[10]=R.drawable.cp10;
  
              //Restore preferences 
              SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
              int storedPreference = preferences.getInt("storedInt", 0);
  
              //Image to use depending on coupon collected
              final ImageView img = new ImageView(this);
  
              if(storedPreference!=10)
              {
                  img.setImageResource(images[storedPreference]);
              }
              else
              {
                  AlertDialog.Builder builder = new AlertDialog.Builder(this);
                  builder.setCancelable(false);
                  builder.setTitle("Redeem Your Coupon?");
                  builder.setInverseBackgroundForced(true);
                  builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                      public void onClick(DialogInterface dialog, int which)
                      {
                          dialog.dismiss();
                          SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
                          SharedPreferences.Editor editor = preferences.edit();
                          editor.putInt("storedInt", 0); // value to store
                          editor.commit();    
                          img.setImageResource(images[0]);
                      }
                  });
                  builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
                      public void onClick(DialogInterface dialog, int which) {
                          dialog.dismiss();
                          img.setImageResource(images[10]);
                      }
                  });
              }
  
  
              //Check and send Intent from NFC tag discovered
              mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
  
              mNfcPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,
                      getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP
                      | Intent.FLAG_ACTIVITY_CLEAR_TOP), 0);
  
  
              IntentFilter coupontag = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
              coupontag.addDataScheme("http");
              coupontag.addDataAuthority("www.ichatime.com", null);
              coupontag.addDataPath(".*", PatternMatcher.PATTERN_SIMPLE_GLOB);
  
              mNdefExchangeFilters = new IntentFilter[] { coupontag };
  
          }
  
          @Override
          public boolean onCreateOptionsMenu(Menu menu) {
              getMenuInflater().inflate(R.menu.activity_main, menu);
              return true;
          }
  
          @Override
          protected void onResume() {
              super.onResume();
              if(mNfcAdapter != null) {
                  mNfcAdapter.enableForegroundDispatch(this, mNfcPendingIntent,
                      mNdefExchangeFilters, null);
              } else {
                  Toast.makeText(getApplicationContext(), "Sorry, No NFC Adapter found.", Toast.LENGTH_SHORT).show();
              }
  
  
          }
  
          @Override
          protected void onPause() {
              super.onPause();
              if(mNfcAdapter != null) mNfcAdapter.disableForegroundDispatch(this);
          }
  
          @Override
          protected void onStop() {
              super.onStop();
  
              // We need an Editor object to make preference changes.
                // All objects are from android.context.Context
                  SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
                  int storedPreference = preferences.getInt("storedInt", 0);
  
                  SharedPreferences.Editor editor = preferences.edit();
                  editor.putInt("storedInt", storedPreference); // value to store
                  editor.commit();    
          }
  
          @Override
          protected void onNewIntent(Intent intent) {
              super.onNewIntent(intent);      
              SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
              int storedPreference = preferences.getInt("storedInt", 0);
  
              if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
                  NdefMessage[] messages = null;
                  Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
                  if (rawMsgs != null) {
                      messages = new NdefMessage[rawMsgs.length];
                      for (int i = 0; i &lt; rawMsgs.length; i++) {
                          messages[i] = (NdefMessage) rawMsgs[i];
                      }
                  }
                  if(messages[0] != null) {
                      String result="";
                      byte[] payload = messages[0].getRecords()[0].getPayload();
                      // this assumes that we get back am SOH followed by host/code
                      for (int b = 1; b&lt;payload.length; b++) { // skip SOH
                          result += (char) payload[b];
                      }
                      if (result == "ichatime.com")
                          {
                          final ImageView img = new ImageView(this);
                          Toast.makeText(getApplicationContext(), "Coupon collected!", Toast.LENGTH_SHORT).show();
  
                          if (storedPreference!=10)
                          {
                              storedPreference++;
                              SharedPreferences.Editor editor = preferences.edit();
                              editor.putInt("storedInt", storedPreference);
                              img.setImageResource(images[storedPreference]);
                          }
                              if (storedPreference==10)
                              {
                                  AlertDialog.Builder builder = new AlertDialog.Builder(this);
                                  builder.setCancelable(false);
                                  builder.setTitle("Redeem Your Coupon?");
                                  builder.setInverseBackgroundForced(true);
                                  builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                                      public void onClick(DialogInterface dialog, int which)
                                      {
                                          dialog.dismiss();
                                          SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
                                          SharedPreferences.Editor editor = preferences.edit();
                                          editor.putInt("storedInt", 0); // value to store
                                          editor.commit();    
                                          img.setImageResource(images[0]);
                                      }
                                  });
                                  builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
                                      public void onClick(DialogInterface dialog, int which) {
                                          dialog.dismiss();
                                          img.setImageResource(images[10]);
                                      }
                                  });
                              }
                          else
                          {
                              SharedPreferences.Editor editor = preferences.edit();
                              editor.putInt("storedInt", 10);
                              img.setImageResource(images[10]);
                          }}
                      else 
                      {
                          Toast.makeText(getApplicationContext(), "Wrong tag detected!", Toast.LENGTH_SHORT).show();
                      }
                      //Debugging Mode to see what is contained in the tags.
              //          Toast.makeText(getApplicationContext(), "Tag Contains " + result, Toast.LENGTH_SHORT).show();
                  }
              }
          }
  
  }
  </code></pre>
  
  <p>Logcat errors:</p>
  
  <pre><code>&gt;11-26 01:16:11.869: D/AndroidRuntime(550): Shutting down VM
  &gt;
  11-26 01:16:11.869: W/dalvikvm(550): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
  &gt;
  11-26 01:16:11.929: I/dalvikvm(550): threadid=3: reacting to signal 3
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550): FATAL EXCEPTION: main
  &gt;
  **11-26 01:16:11.979: E/AndroidRuntime(550): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ponpon/com.example.ponpon.MainActivity}: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ponpon/com.example.ponpon.CouponManager}: java.lang.ArrayIndexOutOfBoundsException: length=10; index=10**
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.os.Handler.dispatchMessage(Handler.java:99)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.os.Looper.loop(Looper.java:137)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.main(ActivityThread.java:4424)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at java.lang.reflect.Method.invokeNative(Native Method)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at java.lang.reflect.Method.invoke(Method.java:511)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at dalvik.system.NativeStart.main(Native Method)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ponpon/com.example.ponpon.CouponManager}: java.lang.ArrayIndexOutOfBoundsException: length=10; index=10
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.startActivityNow(ActivityThread.java:1797)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:135)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:347)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:682)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.widget.TabHost.setCurrentTab(TabHost.java:346)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.widget.TabHost.addTab(TabHost.java:236)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at com.example.ponpon.MainActivity.onCreate(MainActivity.java:37)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.Activity.performCreate(Activity.java:4465)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  ... 11 more
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550): Caused by: java.lang.ArrayIndexOutOfBoundsException: length=10; index=10
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at com.example.ponpon.CouponManager.onCreate(CouponManager.java:53)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.Activity.performCreate(Activity.java:4465)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
  &gt;
  11-26 01:16:11.979: E/AndroidRuntime(550):  ... 21 more
  </code></pre>
  
  <p>What did I do wrong with my arrays? Thanks for the clarification guys!</p>