// SQLite 데이터베이스 백업
File dataDirectory = Environment.getDataDirectory();
File backupDir = new File(Environment.getExternalStorageDirectory(), "app_backup");
File currentDB = new File(dataDirectory, "app_database");
File backupDB = new File(backupDir, "app_backup.db");

try {
    FileChannel src = new FileInputStream(currentDB).getChannel();
    FileChannel dst = new FileOutputStream(backupDB).getChannel();
    dst.transferFrom(src, 0, src.size());
    src.close();
    dst.close();
} catch (IOException e) {
    e.printStackTrace();
}

// 외부 저장소에 데이터 저장
File dataFile = new File(getExternalFilesDir(null), "data.txt");
try {
    FileOutputStream fos = new FileOutputStream(dataFile);
    fos.write(data.getBytes());
    fos.close();
} catch (IOException e) {
    e.printStackTrace();
}