Caused by: java.lang.NullPointerException

XXXX.onCreate(MainWindow.java:100)
02-16 12:34:52.029: E/AndroidRuntime(345):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-16 12:34:52.029: E/AndroidRuntime(345):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)

이렇게 로그가 뜨네요..ㅠ

 

소스 일부분만 찾아서 올립니다..어찌해야할까요..조언좀 부탁드려요..꾸벅꾸벅..ㅠ

 

public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  showFirstStartUpDialogIfPrefsEmpty();
  getContentResolver().registerContentObserver(RosterProvider.GROUPS_URI,
    true, mRosterObserver);
  registerXMPPService();
  createUICallback();
  requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
 
  registerListAdapter();

  actionBar = (ActionBar) findViewById(R.id.actionbar);
  actionBar.setTitle(R.string.app_name);
  actionBar.setSubTitle(mStatusMessage);

  toggleOfflineContactsAction = new ToggleOfflineContactsAction();
  actionBar.addAction(toggleOfflineContactsAction);

  changeStatusAction = new ChangeStatusAction();
  actionBar.setHomeAction(changeStatusAction);
 }