show download progress bar

Question

I'm using an executor service in my app to download a file from a URL. I want to add a horizontal progress bar to show the download progress, but I'm facing some errors. How can I add a progress bar in the following code, without using async task?

private class ExecutorServiceDownload implements Runnable {
    private String url;

    public ExecutorServiceDownload(String url) {
        this.url = url;
    }

    @Override
    public void run() {
        dlFile(url);
    }

    private String dlFile(String surl) {


        try {

            // I added progressbar here and it didn't download anything 

            InputStream input = null;
            OutputStream output = null;
            HttpURLConnection connection = null;

            URL url = new URL(surl);
            connection = (HttpURLConnection) url.openConnection();
            connection.connect();

            if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
                return "Server returned HTTP " + connection.getResponseCode() + " " + connection.getResponseMessage();

            input = connection.getInputStream();
            String title = URLUtil.guessFileName(String.valueOf(url), null, null);
            output = new FileOutputStream(Environment.getExternalStorageDirectory().toString() + "/test_files" + "/" + title);
            int contentLength = connection.getContentLength();

            byte data[] = new byte[4096];
            long total = 0;
            int count;
            while ((count = input.read(data)) != -1) {
                total += count;
                output.write(data, 0, count);
            }
        } catch (Exception e) {
            return e.toString();
        }
        return null;
    }
}

Answer 1

Use this code to download a file with executor service:

in onCreate:

ProgressBar progressBar;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        progressBar = findViewById(R.id.progressbar);

        downloading(); // to start the download

Downloading file with executor service:

private void downloading() {
    progressBar.setVisibility(View.VISIBLE);

    ExecutorService executor = Executors.newSingleThreadScheduledExecutor();
    Handler handler = new Handler(Looper.getMainLooper());

    executor.execute(new Runnable() {

        int count;

        @Override
        public void run() {

            // Background work here
            try {

                // put your url here, this is an example
                URL url = new URL("http://techslides.com/demos/sample-videos/small.mp4");
                URLConnection conection = url.openConnection();
                conection.connect();

                int lenghtOfFile = conection.getContentLength();

                // download the file

                InputStream input = conection.getInputStream();

                // catalogfile is your destenition folder
                OutputStream output = new FileOutputStream(catalogfile + "video.mp4");

                byte data[] = new byte[1024];

                long total = 0;

                while ((count = input.read(data)) != -1) {
                    total += count;
                    
                    // publishing the progress
                    publishProgress(Integer.valueOf("" + (int)((total * 100) / lenghtOfFile)));

                    // writing data to file
                    output.write(data, 0, count);
                }

                // flushing output
                output.flush();

                // closing streams
                output.close();
                input.close();

                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        // UI Thread work here
                        progressBar.setVisibility(View.GONE);
                    }
                });
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });

}

update progressbar

private void publishProgress(Integer...progress) {
    progressBar.setProgress(progress[0]);
}

and for the horizontal progress bar, use:

 <ProgressBar
    android:max="100"
    style="?android:attr/progressBarStyleHorizontal"
    android:visibility="invisible"
    android:id="@+id/progressbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"