Database won't remove when uninstall the Android Application

Question

I have two major questions.

1. Database won't delete when uninstall app.
2. Downloaded files won't delete while unstable the app.

There is a database in my android application. I create it by java

class as follows.

public DataBaseHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

public DataBaseHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version, DatabaseErrorHandler errorHandler) {
    super(context, name, factory, version, errorHandler);
}

@Override
public void onCreate(SQLiteDatabase db) {
    // creating required tables
    db.execSQL(CREATE_TABLE_QUOTES);
    db.execSQL(CREATE_TABLE_FILTERS);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // on upgrade drop older tables
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUOTES);
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUOTES);
    // create new tables
    onCreate(db);
}

There is no specific path defined at the code for database.

This is the code how I download files. And there is specific path, But it is not allowed to create folder in Android>data>com.myapp as well.

public String downloadImage(String img_url, int i) {
        File sdCard = Environment.getExternalStorageDirectory();
        File dir = new File (sdCard.getAbsolutePath() + "/fog/images/filters");
        // Make sure the Pictures directory exists.
        dir.mkdirs();
        File destinationFile = new File(dir, "filter"+i);
        String filepath = null;
        try{
            URL url = new URL("http://fog.wrapper.io/uploads/category/"+img_url+".png");

            HttpURLConnection conection = (HttpURLConnection)url.openConnection();
            conection.setRequestMethod("GET");
            conection.setRequestProperty("Content-length", "0");
            conection.setUseCaches(false);
            conection.setAllowUserInteraction(false);
            conection.connect();

            int status = conection.getResponseCode();

            switch (status) {
                case 200:
                case 201:
                    FileOutputStream fileOutput = new FileOutputStream(destinationFile);
                    InputStream inputStream = conection.getInputStream();
                    int totalSize = conection.getContentLength();
                    int downloadedSize = 0;
                    byte[] buffer = new byte[1024];
                    int bufferLength = 0;
                    while ( (bufferLength = inputStream.read(buffer)) > 0 )
                    {
                        fileOutput.write(buffer, 0, bufferLength);
                        downloadedSize += bufferLength;                            Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
                    }
                    fileOutput.close();
                    if(downloadedSize==totalSize) filepath = destinationFile.getPath();
                   Log.i("filepath:"," "+filepath) ;
                    return filepath;
            }

        } catch (IOException e) {
            Log.d("ImageManager", "Error: " + e);
        }
        return null;
    }
} // Get filters

Please help me. Sorry for bad English.

Answer 1

in Android 6.0, google added new feature called Auto Backup.

when this option is on(default is on), Android system copies almost every directories and files that created by system, and upload it to user's google drive account.

When user reinstalls app, android automatically restore app's data, no matter how it was installed(via Play store, adb install, initial device setup).

The restore operation occurs after the APK is installed, but before the app is available to be launched by the user.

android developers page : https://developer.android.com/guide/topics/data/autobackup.html