Search xml parse

i am new in android. I have an XML file that I am trying to search using Java. (the problem is in the edit text) my code need edit how i can do a search that get text from edit text and filter the result in listview? this is my code:

package com.search.xmlParsing;



public class MainActivity extends ListActivity {

public static final String LOGTAG = "EXPLORECA";
public static final String USERNAME = "pref_username";
public static final String VIEWIMAGE = "pref_viewimages";
private static final int TOUR_DETAIL_ACTIVITY = 1001;
private SharedPreferences settings;
private OnSharedPreferenceChangeListener listener;
private List<Tour> tours;
boolean isMyTours;
ToursDataSource datasource;
ArrayAdapter<Tour> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    /*
     * ArrayAdapter<Tour> adapter = new TourListAdapter(this, tours);
     * setListAdapter(adapter);
     */
    final EditText editText = (EditText) findViewById(R.id.editTextSearch);

    editText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence cs, int arg1, int arg2,
                int arg3) {
        }

        @Override
        public void beforeTextChanged(CharSequence arg0, int arg1,
                int arg2, int arg3) {
        }

        @Override
        public void afterTextChanged(Editable arg0) {
        MainActivity.this.adapter.getFilter().filter(arg0);
            /*
             * final Intent queryIntent = getIntent(); final String
             * queryAction = queryIntent.getAction(); if
             * (Intent.ACTION_SEARCH.equals(queryAction)) {
             * doSearchQuery(queryIntent, "onNewIntent()"); } else { //
             * mDeliveredByText
             * .setText("onNewIntent(), but no ACTION_SEARCH intent"); }
             */
        }
    });
    settings = PreferenceManager.getDefaultSharedPreferences(this);

    listener = new OnSharedPreferenceChangeListener() {

        @Override
        public void onSharedPreferenceChanged(
                SharedPreferences sharedPreferences, String key) {
            MainActivity.this.refreshDisplay();
        }
    };
    settings.registerOnSharedPreferenceChangeListener(listener);

    datasource = new ToursDataSource(this);
    datasource.open();

    tours = datasource.findAll();
    if (tours.size() == 0) {
        createData();
        tours = datasource.findAll();
    }
    isMyTours = false;

    refreshDisplay();

}

public void refreshDisplay() {

    boolean viewImages = settings.getBoolean(VIEWIMAGE, true);

    if (viewImages) {
        ArrayAdapter<Tour> adapter = new TourListAdapter(this, tours);
        setListAdapter(adapter);
    } else {
        ArrayAdapter<Tour> adapter = new ArrayAdapter<Tour>(this,
                android.R.layout.simple_list_item_1, tours);
        setListAdapter(adapter);
    }

}

@Override
protected void onResume() {
    super.onResume();
    datasource.open();
}

@Override
protected void onPause() {
    super.onPause();
    datasource.close();
}

private void createData() {
    ToursPullParser parser = new ToursPullParser();
    List<Tour> tours = parser.parseXML(this);

    for (Tour tour : tours) {
        datasource.create(tour);
    }
}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    Tour tour = tours.get(position);
    Intent intent = new Intent(this, TourDetailActivity.class);
    intent.putExtra(".model.Tour", tour);
    intent.putExtra("isMyTours", isMyTours);
    startActivityForResult(intent, TOUR_DETAIL_ACTIVITY);

}

/*
 * @Override protected void onActivityResult(int requestCode, int
 * resultCode, Intent data) { super.onActivityResult(requestCode,
 * resultCode, data);
 * 
 * if (requestCode == TOUR_DETAIL_ACTIVITY && resultCode == -1) {
 * datasource.open(); tours = datasource.findMyTours(); refreshDisplay();
 * isMyTours = true;
 * 
 * } }
 */
/*
 * private void doSearchQuery(final Intent queryIntent, final String
 * entryPoint) {
 * 
 * // The search query is provided as an "extra" string in the query intent
 * final String queryString =
 * queryIntent.getStringExtra(SearchManager.QUERY); //
 * mQueryText.setText(queryString);
 * 
 * // Record the query string in the recent queries suggestions provider. //
 * SearchRecentSuggestions suggestions = new SearchRecentSuggestions(this,
 * // SearchSuggestionSampleProvider.AUTHORITY,
 * SearchSuggestionSampleProvider.MODE); //
 * suggestions.saveRecentQuery(queryString, null); final Bundle appData =
 * queryIntent.getBundleExtra(SearchManager.APP_DATA); if (appData == null)
 * { // mAppDataText.setText("<no app data bundle>"); } if (appData != null)
 * { String testStr = appData.getString("demo_key"); //
 * mAppDataText.setText((testStr == null) ? "<no app data>" : testStr); }
 * 
 * // mDeliveredByText.setText(entryPoint);
 * 
 * }
 */
}

but it force close !!!!