Question

I’m making a android library app that can download and show special files. now I need to write a service that download file in background! are there samples for services?

and I want to save files in SD, because users can update app and don’t should miss downloaded files.

If you have a suggest or opinion for this, write me, please.

Answer 1

try {
    URL url = new URL("url from apk file is to be downloaded");
    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.setDoOutput(true);
    urlConnection.connect();

    File sdcard = Environment.getExternalStorageDirectory();
    File file = new File(sdcard, "filename.ext");

    FileOutputStream fileOutput = new FileOutputStream(file);
    InputStream inputStream = urlConnection.getInputStream();

    byte[] buffer = new byte[1024];
    int bufferLength = 0;

    while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
        fileOutput.write(buffer, 0, bufferLength);
    }
    fileOutput.close();

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

Permission: To write to external storage, you need to add this permission:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Note: you can use above code to get the file downloaded and saved in the SD card. You can run this code in background using AsysnTask or thread.