Error: java.lang.NullPointerException en android.support.v4.content.Loader

Quiero implementar LoaderManager en mi aplicación para reducir el tiempo de inicio Como se puede ver aquí, pero después de implementar la sugerencia en ese hilo que estaba recibiendo el siguiente error initLoader(int, Bundle, LoaderManager.LoaderCallbacks) in the type LoaderManager is not applicable for the arguments (int, null, MainActivity) . Después de buscar aquí encontré la solución para ese segundo error aquí . Pero después de implementar la sugerencia de más tarde, ahora estoy recibiendo el error java.lang.NullPointerException at android.support.v4.content.Loader . Estoy poniendo el código que tengo actualmente, ¿puede alguien decirme, ¿cómo puedo resolver este problema

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Gato de registro

 10-03 20:11:34.849: E/AndroidRuntime(2968): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.sms.it/com.test.sms.it.MainActivity}: java.lang.NullPointerException 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.os.Handler.dispatchMessage(Handler.java:99) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.os.Looper.loop(Looper.java:123) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.ActivityThread.main(ActivityThread.java:3683) 10-03 20:11:34.849: E/AndroidRuntime(2968): at java.lang.reflect.Method.invokeNative(Native Method) 10-03 20:11:34.849: E/AndroidRuntime(2968): at java.lang.reflect.Method.invoke(Method.java:507) 10-03 20:11:34.849: E/AndroidRuntime(2968): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 10-03 20:11:34.849: E/AndroidRuntime(2968): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 10-03 20:11:34.849: E/AndroidRuntime(2968): at dalvik.system.NativeStart.main(Native Method) 10-03 20:11:34.849: E/AndroidRuntime(2968): Caused by: java.lang.NullPointerException 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.support.v4.content.Loader.<init>(Loader.java:91) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.support.v4.content.AsyncTaskLoader.<init>(AsyncTaskLoader.java:92) 10-03 20:11:34.849: E/AndroidRuntime(2968): at com.test.sms.it.MainActivity$ContactsDataLoader.<init>(MainActivity.java:104) 10-03 20:11:34.849: E/AndroidRuntime(2968): at com.test.sms.it.MainActivity.onCreateLoader(MainActivity.java:496) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.support.v4.app.LoaderManagerImpl.createLoader(LoaderManager.java:487) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.support.v4.app.LoaderManagerImpl.createAndInstallLoader(LoaderManager.java:496) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.support.v4.app.LoaderManagerImpl.initLoader(LoaderManager.java:550) 10-03 20:11:34.849: E/AndroidRuntime(2968): at com.test.sms.it.MainActivity.onCreate(MainActivity.java:91) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 10-03 20:11:34.849: E/AndroidRuntime(2968): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 

MainActivity.java

 import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import android.app.AlertDialog; import android.app.ProgressDialog; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.SharedPreferences; import android.database.Cursor; import android.graphics.Color; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.net.Uri; import android.os.AsyncTask; import android.os.Bundle; import android.preference.PreferenceManager; import android.provider.ContactsContract; import android.support.v4.app.FragmentActivity; import android.support.v4.app.LoaderManager; import android.support.v4.content.AsyncTaskLoader; import android.support.v4.content.Loader; import android.view.KeyEvent; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.AutoCompleteTextView; import android.widget.Button; import android.widget.EditText; import android.widget.SimpleAdapter; import android.widget.Spinner; import android.widget.Toast; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.activity_main); editUser1UserName = (EditText) findViewById(R.id.editTextUser1UserName); editUser1Password = (EditText) findViewById(R.id.editTextUser1Password); editUser2UserName = (EditText) findViewById(R.id.editTextUser2UserName); editUser2Password = (EditText) findViewById(R.id.editTextUser2Password); editUser3UserName = (EditText) findViewById(R.id.editTextUser3UserName); editUser3Password = (EditText) findViewById(R.id.editTextUser3Password); editUser4UserName = (EditText) findViewById(R.id.editTextUser4UserName); editUser4Password = (EditText) findViewById(R.id.editTextUser4Password); editUser5UserName = (EditText) findViewById(R.id.editTextUser5UserName); editUser5Password = (EditText) findViewById(R.id.editTextUser5Password); mTxtPhoneNo = (AutoCompleteTextView) findViewById(R.id.mmWhoNo); mTxtPhoneNo.setThreshold(1); mTxtPhoneNo.setTextColor(Color.BLACK); editText = (EditText) findViewById(R.id.editTextMessage); spinner1 = (Spinner) findViewById(R.id.spinnerGateway); btnsend = (Button) findViewById(R.id.btnSend); btnContact = (Button) findViewById(R.id.btnContact); btnClear = (Button) findViewById(R.id.btnClear); btnClear.setOnClickListener(this); btnsend.setOnClickListener(this); btnContact.setOnClickListener(this); mPeopleList = new ArrayList<Map<String, String>>(); getSupportLoaderManager().initLoader(0, null, this); mTxtPhoneNo.setOnItemClickListener(this); readPerson(); Panel panel; topPanel = panel = (Panel) findViewById(R.id.mytopPanel); panel.setOnPanelListener(this); panel.setInterpolator(new BounceInterpolator(Type.OUT)); getLoginDetails(); } public class ContactsDataLoader extends AsyncTaskLoader<ArrayList<Map<String, String>>> { public ContactsDataLoader(Context context) { super(context); } @Override public ArrayList<Map<String, String>> loadInBackground() { mPeopleList.clear(); Cursor people = getContentResolver().query( ContactsContract.Contacts.CONTENT_URI, null, null, null, null); while (people.moveToNext()) { String contactName = people .getString(people .getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)); String contactId = people.getString(people .getColumnIndex(ContactsContract.Contacts._ID)); String hasPhone = people .getString(people .getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER)); if ((Integer.parseInt(hasPhone) > 0)) { Cursor phones = getContentResolver().query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " = " + contactId, null, null); while (phones.moveToNext()) { String phoneNumber = phones .getString(phones .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)); String numberType = phones .getString(phones .getColumnIndex(ContactsContract.CommonDataKinds.Phone.TYPE)); Map<String, String> NamePhoneType = new HashMap<String, String>(); NamePhoneType.put("Name", contactName); NamePhoneType.put("Phone", phoneNumber); if (numberType.equals("0")) NamePhoneType.put("Type", "Work"); else if (numberType.equals("1")) NamePhoneType.put("Type", "Home"); else if (numberType.equals("2")) NamePhoneType.put("Type", "Mobile"); else NamePhoneType.put("Type", "Other"); mPeopleList.add(NamePhoneType); } phones.close(); } } people.close(); startManagingCursor(people); return mPeopleList; } @Override protected void onStartLoading() { super.onStartLoading(); forceLoad(); } } public Loader<ArrayList<Map<String, String>>> onCreateLoader(int id, Bundle args) { return new ContactsDataLoader(context); } public void onLoadFinished(Loader<ArrayList<Map<String, String>>> loader, ArrayList<Map<String, String>> data) { mPeopleList = data; mAdapter = new SimpleAdapter(this, mPeopleList, R.layout.custcontview, new String[] { "Name", "Phone", "Type" }, new int[] { R.id.ccontName, R.id.ccontNo, R.id.ccontType }); mTxtPhoneNo.setAdapter(mAdapter); } public void onLoaderReset(Loader<ArrayList<Map<String, String>>> loader) { mPeopleList = new ArrayList<Map<String, String>>(); mAdapter = new SimpleAdapter(this, mPeopleList, R.layout.custcontview, new String[] { "Name", "Phone", "Type" }, new int[] { R.id.ccontName, R.id.ccontNo, R.id.ccontType }); mTxtPhoneNo.setAdapter(mAdapter); } 

 public Loader<ArrayList<Map<String, String>>> onCreateLoader(int id, Bundle args) { return new ContactsDataLoader(this); }