private void checkDataBase() {
    SQLiteDatabase checkDB = null;
    try {
        checkDB = SQLiteDatabase.openDatabase(getApplicationContext().getDatabasePath(DB_NAME).getPath(), null, SQLiteDatabase.OPEN_READONLY);
    } catch (SQLiteException e) {
        e.printStackTrace();
    }

    if (checkDB != null) {
        checkDB.close();
    } else {
        try {
            copyDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

private void copyDataBase() throws IOException {
    InputStream myInput = getApplicationContext().getAssets().open(DB_NAME);
    OutputStream myOutput = new FileOutputStream(getApplicationContext().getDatabasePath(DB_NAME).getPath());
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer)) > 0) {
        myOutput.write(buffer, 0, length);
    }
    myOutput.flush();
    myOutput.close();
    myInput.close();
}