service - Progress Bar % completed (download) Display in Android

Question

I have a problem with Progress Bar showing % of download completed. I have a service class in which the downloading takes place. I can get the start time and end time of download from this class. In Main Activity on clicking a button I have to show the progress %. I heard that its possible through AsyncTask but I have no clue about how it works. Please help me with some sample code example related to this. Thanks

Answer 1

I would prefer AsyncTask for this.

Here's an example

ProgressDialog mProgressDialog;
// instantiate it within the onCreate method
mProgressDialog = new ProgressDialog(YourActivity.this);
mProgressDialog.setMessage("A message");
mProgressDialog.setIndeterminate(false);
mProgressDialog.setMax(100);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);

// execute this when the downloader must be fired
DownloadFile downloadFile = new DownloadFile();
downloadFile.execute("the url to the file you want to download");

here's the AsyncTask

private class DownloadFile extends AsyncTask<String, Integer, String> {
@Override
protected String doInBackground(String... sUrl) {
    try {
        URL url = new URL(sUrl[0]);
        URLConnection connection = url.openConnection();
        connection.connect();
        // this will be useful so that you can show a typical 0-100% progress bar
        int fileLength = connection.getContentLength();

        // download the file
        InputStream input = new BufferedInputStream(url.openStream());
        OutputStream output = new FileOutputStream("/sdcard/file_name.extension");

        byte data[] = new byte[1024];
        long total = 0;
        int count;
        while ((count = input.read(data)) != -1) {
            total += count;
            // publishing the progress....
            publishProgress((int) (total * 100 / fileLength));
            output.write(data, 0, count);
        }

        output.flush();
        output.close();
        input.close();
    } catch (Exception e) {
    }
    return null;
}

This can be done using Download from Service as well as Download Manager class. Refer this question for details.

EDIT

The percentage completed is what you actually publish in the progress dialog. If you want to display the percentage, you may use this (total * 100 / fileLength).

int percentage =  (total * 100 / fileLength);
TextView tv = (TextView)findViewById(R.id.textview);
tv.setText("" + percentage);

Use this code to display the percentage in the desired textview.