Random number Java

/data/data/<package>/shared_prefs/<package>_preferences.xml

String TAG = "MyActivityName";
File f = new File("/data/data/"+this.getPackageName()
+"/shared_prefs/"+this.getPackageName()+"_preferences.xml");
if(f.exists())
	Log.d(TAG, "exist");
else
	Log.d(TAG, "not exist");

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GREEN);
            
           Bitmap b = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
           Canvas c = new Canvas(b);
           RectF rectF = new RectF();
           rectF.set(5,5,150,150);
           c.drawRoundRect(rectF, 10, 10, paint);
           
            paint.setColor(Color.RED);
           
           canvas.drawBitmap(b, 10,10, paint);
		}

	}
}

    @Override
	protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
        setContentView(R.layout.main.xml);
        getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title);
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="//schemas.android.com/apk/res/android" android:id="@+id/screen"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:orientation="vertical">
    <TextView android:id="@+id/left_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:text="Some text" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
       
        android:src="@drawable/ic_launcher" />
    
</RelativeLayout>

public class DictionaryProvider extends ContentProvider {
    String TAG = "DictionaryProvider";

//    public static String AUTHORITY = "com.example.android.searchabledict.DictionaryProvider";
// change to your new package name
public static String AUTHORITY = "com.myweb.mysubdomen.searchabledict.DictionaryProvider";
    public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/dictionary");


// in AndroidManifest.xml
//change com.example.android to your package e.g. com.myweb.mysubdomen
<!-- Provides search suggestions for words and their definitions. -->
        <provider android:name="com.example.android.searchabledict.DictionaryProvider"
            android:configChanges="keyboard|keyboardHidden|orientation"
                  android:authorities="com.example.android.searchabledict.DictionaryProvider" />

        <!-- Points to searchable activity so the whole app can invoke search. -->
        <meta-data android:name="android.app.default_searchable"
            android:configChanges="keyboard|keyboardHidden|orientation"
                   android:value=".SearchableDictionary" />

// I change like this:
        <!-- Provides search suggestions for words and their definitions. -->
        <provider android:name=".DictionaryProvider"
            android:configChanges="keyboard|keyboardHidden|orientation"
                  android:authorities="cz.okhelp.android.searchabledict.DictionaryProvider" />

        <!-- Points to searchable activity so the whole app can invoke search. -->
        <meta-data android:name="android.app.default_searchable"
            android:configChanges="keyboard|keyboardHidden|orientation"
                   android:value=".SearchableDictionary" />

<searchable xmlns:android="//schemas.android.com/apk/res/android"
        android:label="@string/search_label"
        android:hint="@string/search_hint"
        android:searchSettingsDescription="@string/settings_description"
        android:searchSuggestAuthority="cz.okhelp.android.searchabledict.DictionaryProvider"
        android:searchSuggestIntentAction="android.intent.action.VIEW"
        android:searchSuggestIntentData="content://cz.okhelp.android.searchabledict.DictionaryProvider/dictionary"
        android:searchSuggestSelection=" ?"
        android:searchSuggestThreshold="1"
        android:includeInGlobalSearch="true"
        >
 </searchable>

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        final AssetManager assetManager = getAssets();
        try {
			// for assets folder add empty string
                        String[] filelist = assetManager.list("");
                        // for assets/subFolderInAssets add only subfolder name
                        String[] filelistInSubfolder = assetManager.list("subFolderInAssets");
			if (filelist == null) {
			    // dir does not exist or is not a directory
			} else {
			    for (int i=0; i<filelist.length; i++) {
			        // Get filename of file or directory
			        String filename = filelist[i];
			    }
			}
                     
                        // if(filelistInSubfolder == null) ............  

		} catch (IOException e) {
			e.printStackTrace();
		}
     }