Develop Reference

Trying to add Notification Builder in AsyncTask

Someone helps me out Pls
I wanted to implement a notification builder in my AsyncTask method for downloading files from the server. Notification that contains progress bar with incrementing base on file length, show download percentage and how many MB remain, with pause and resume, I try it but still notification not showing while downloading is doing in the background there is my code:
class DownloadFileFromURL extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(progress_bar_type);
}
#Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
int lenghtOfFile = conection.getContentLength();
InputStream input = new BufferedInputStream(url.openStream(), 8192);
String folder = "/data/data/" + getPackageName() + "/files/";
File directory = new File(folder);
if (!directory.exists()) {
directory.mkdirs();
}
OutputStream output = new FileOutputStream(folder + getIntent().getStringExtra("title") + ".mp4");
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
publishProgress(""+(int)((total*100)/lenghtOfFile));
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
protected void onProgressUpdate(String... progress) {
pDialog.setProgress(Integer.parseInt(progress[0]));
}
#Override
protected void onPostExecute(String file_url) {
dismissDialog(progress_bar_type);
String type = "downloads";
Update(type);
View layout = getLayoutInflater().inflate(R.layout.toast_custom, findViewById(R.id.custom_toast_layout_id));
TextView text = layout.findViewById(R.id.text);
text.setText(getIntent().getStringExtra("title") + " - Downloaded Successfully!");
Toast toast = new Toast(getApplicationContext());
toast.setDuration(Toast.LENGTH_LONG);
toast.setView(layout);
toast.show();
}
}

Where is the code to show Notification and which android version os are you using ?

How to Cast Fragment to Async Constructor?

I want to cast SlideshowDialogFragment to context in my asynctask in DdownloadTask.java but when i write
final DownloadTask downloadTask = new
DownloadTask(myActivity.this);
SlideshowDialogFragment instead of myActivity , android show warning and say
warning android
i don't know what am i do ?? thx for help me
public class SlideshowDialogFragment extends DialogFragment{
ArrayList<Image> images;
ViewPager viewPager;
MyViewPagerAdapter myViewPagerAdapter;
TextView lblCount,lblTitle,lblDate;
Button btn_set;
Button btn_download;
int selectedPostition;
DownloadManager downloadManager;
public static ProgressDialog mProgressDialog;
static SlideshowDialogFragment newInstance(){
SlideshowDialogFragment f=new SlideshowDialogFragment();
return f;
}
#Override
public View onCreateView (LayoutInflater inflater,ViewGroup container,Bundle saveInstanceState)
{
View v=inflater.inflate(R.layout.fragment_image_slider,container,false);
viewPager=(ViewPager)v.findViewById(R.id.view_pager);
lblTitle=(TextView)v.findViewById(R.id.title);
lblDate=(TextView)v.findViewById(R.id.date);
btn_set=(Button)v.findViewById(R.id.btn_set);
btn_download=(Button)v.findViewById(R.id.btn_download);
images=(ArrayList<Image>) getArguments().getSerializable("images");
selectedPostition=getArguments().getInt("position");
myViewPagerAdapter=new MyViewPagerAdapter();
viewPager.setAdapter(myViewPagerAdapter);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int
positionOffsetPixels) {
displayInfo(position);
//setWallpaper(position);
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
setCurrentItem(selectedPostition);
btn_download.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
download(selectedPostition);
}
});
return v;
}
void download (int position){
Image image=images.get(position);
String large = image.getlarge();
final DownloadTask downloadTask = new
DownloadTask(**SlideshowDialogFragment**.this);
downloadTask.execute(large);
}
And this is DownloadTask Activity with constructor i write AsyncTask in this class:
public class DownloadTask extends AsyncTask<String, Integer, String> {
private Context context;
private PowerManager.WakeLock mWakeLock;
public DownloadTask(Context context) {
this.context = context;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
// take CPU lock to prevent CPU from going off if the user
// presses the power button during download
PowerManager pm = (PowerManager)
context.getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
getClass().getName());
mWakeLock.acquire();
mProgressDialog.show();
}
#Override
protected void onProgressUpdate(Integer... progress) {
super.onProgressUpdate(progress);
// if we get here, length is known, now set indeterminate to false
mProgressDialog.setIndeterminate(false);
mProgressDialog.setMax(100);
mProgressDialog.setProgress(progress[0]);
}
#Override
protected void onPostExecute(String result) {
mWakeLock.release();
mProgressDialog.dismiss();
if (result != null)
Toast.makeText(context,"خطای دانلود "+result, Toast.LENGTH_LONG).show();
else
Toast.makeText(context,"دانلود با موفقیت انجام شد",
Toast.LENGTH_SHORT).show();
}
#Override
protected String doInBackground(String... sUrl) {
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
URL url = new URL(sUrl[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
// expect HTTP 200 OK, so we don't mistakenly save error report
// instead of the file
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return "Server returned HTTP " + connection.getResponseCode()
+ " " + connection.getResponseMessage();
}
// this will be useful to display download percentage
// might be -1: server did not report the length
int fileLength = connection.getContentLength();
// download the file
input = connection.getInputStream();
output = new FileOutputStream("/sdcard/tabriz.jpg");
byte data[] = new byte[4096];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
// allow canceling with back button
if (isCancelled()) {
input.close();
return null;
}
total += count;
// publishing the progress....
if (fileLength > 0) // only if total length is known
publishProgress((int) (total * 100 / fileLength));
output.write(data, 0, count);
}
} catch (Exception e) {
return e.toString();
} finally {
try {
if (output != null)
output.close();
if (input != null)
input.close();
} catch (IOException ignored) {
}
if (connection != null)
connection.disconnect();
}
return null;
}
}
what am i do for casting SlideshowDialogFragment to Async ?

You need to pass a Context as you defined your constructor like that. A Fragment does not have a Context, but the Activity has it. Since Fragment is a part of an Activity you can access it with
SlideshowDialogFragment.this.getActivity();
You could also use it directly with DownloadTask(getActivity())

Download PDF not working

In my application, I have an expandablelistview and I want to open a PDF downloaded from the internet when I click on a specific child. The problem is that the pdf file (Read.pdf) is always empty, meaning that the download is not working.
Downloader Class:
public class Downloader {
public static void DownloadFile(String fileURL, File directory) {
try {
FileOutputStream f = new FileOutputStream(directory);
URL u = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
InputStream in = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = in.read(buffer)) > 0) {
f.write(buffer, 0, len1);
}
f.close();
} catch (Exception e) {
e.printStackTrace();
}
}
Part of the Activity:
private void registerClick() {
expListView.setOnChildClickListener(new OnChildClickListener() {
#Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
if ((groupPosition == 0) && (childPosition == 0)){
File file = new File(Environment.getExternalStorageDirectory()+File.separator+"IAVE", "Read.pdf");
try {
file.createNewFile();
} catch (IOException e1) {
e1.printStackTrace();
}
Downloader.DownloadFile("https://www.cp.pt/StaticFiles/Passageiros/1_horarios/horarios/PDF/lx/linha_cascais.pdf", file);
AbrirPDF.showPdf();
} else {
}
return false;
}
});
}
I think the OpenPDF (AbrirPDF) doesn't have any problem, but I will post it...
public class AbrirPDF {
public static void showPdf()
{
File file = new File(Environment.getExternalStorageDirectory()+File.separator+"IAVE/Read.pdf");
PackageManager packageManager = ContextGetter.getAppContext().getPackageManager();
Intent testIntent = new Intent(Intent.ACTION_VIEW);
testIntent.setType("application/pdf");
List list = packageManager.queryIntentActivities(testIntent, PackageManager.MATCH_DEFAULT_ONLY);
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
Uri uri = Uri.fromFile(file);
intent.setDataAndType(uri, "application/pdf");
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
ContextGetter.getAppContext().startActivity(intent);
}
}
Thank you.

Ideally, your download should happen in a separate thread to avoid locking your app.
Here is an example that also includes a progress bar.
public class MainActivity extends Activity {
private ProgressDialog pDialog;
public static final int progress_bar_type = 0;
private static String file_url = "https://www.cp.pt/StaticFiles/Passageiros/1_horarios/horarios/PDF/lx/linha_cascais.pdf";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new DownloadFileFromURL().execute(file_url);
}
#Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case progress_bar_type: // we set this to 0
pDialog = new ProgressDialog(this);
pDialog.setMessage("Downloading file. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setMax(100);
pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pDialog.setCancelable(true);
pDialog.show();
return pDialog;
default:
return null;
}
}
class DownloadFileFromURL extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(progress_bar_type);
}
#Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// this will be useful so that you can show a tipical 0-100%
// progress bar
int lenghtOfFile = conection.getContentLength();
// download the file
InputStream input = new BufferedInputStream(url.openStream(),
8192);
// Output stream
OutputStream output = new FileOutputStream(Environment
.getExternalStorageDirectory().toString()
+ "/2011.kml");
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
// publishing the progress....
// After this onProgressUpdate will be called
publishProgress("" + (int) ((total * 100) / lenghtOfFile));
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
protected void onProgressUpdate(String... progress) {
// setting progress percentage
pDialog.setProgress(Integer.parseInt(progress[0]));
}
#Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after the file was downloaded
dismissDialog(progress_bar_type);
}
}
}

AsyncTask is publishing progress after cancelled

My situation is a RecyclerView of invoices that can be downloaded. They have an action that starts the download and shows the progress in a circular progress view around the download button itself. I use an AsyncTask to download the particular invoice in PDF format, with a custom listener so I know when is cancelled, executed and progress updated outside the AsyncTask itself (to avoid passing the View and updating it inside the AsyncTask mostly).
This is my AsyncTask so far:
public class DownloadTask extends AsyncTask<URL, Integer, String> implements Codes {
private AsyncTaskProgressListener listener;
private File file;
public DownloadTask(AsyncTaskProgressListener listener) {
this.listener = listener;
}
#Override
protected String doInBackground(URL... urls) {
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
URL url = urls[0];
file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/" + url.getFile());
connection = (HttpURLConnection) url.openConnection();
connection.connect();
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return "Server returned HTTP " + connection.getResponseCode()
+ " " + connection.getResponseMessage();
}
int fileLength = connection.getContentLength();
LogUtil.log("" + fileLength);
// download the file
input = connection.getInputStream();
output = new FileOutputStream(new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), url.getFile()));
byte data[] = new byte[4096];
long total = 0;
int count;
int lastProgress = 0;
while ((count = input.read(data)) != -1) {
if (isCancelled()) {
break;
}
total += count;
// publishing the progress....
int progress = 0;
if (fileLength > 0) {
// only if total length is known
progress = (int) (total * 100 / fileLength);
}
//Prevent publishing the same progress various times as it would freeze the progress bar.
if (progress > lastProgress) {
publishProgress(progress);
lastProgress = progress;
}
output.write(data, 0, count);
}
} catch (Exception e) {
LogUtil.log(e.toString());
return e.toString();
} finally {
try {
if (output != null)
output.close();
if (input != null)
input.close();
} catch (IOException e) {
e.printStackTrace();
}
if (connection != null)
connection.disconnect();
}
return null;
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
listener.onProgressUpdated(values[0]);
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
listener.onCompleted();
}
#Override
protected void onCancelled(String s) {
listener.onCancel();
file.delete();
LogUtil.log("CANCELED");
super.onCancelled(s);
//noinspection ResultOfMethodCallIgnored
}
}
And my listener:
tasks[0] = new DownloadTask(new AsyncTaskProgressListener() {
#Override
public void onCompleted() {
state = INVOICE_DOWNLOADED;
}
#Override
public void onCancel() {
state = INVOICE_NOT_DOWNLOADED;
progressView.resetAnimation();
}
#Override
public void onProgressUpdated(int progress) {
progressView.setProgress(progress);
}
});
This is what's called when I press the cancel button:
progressView.setProgress(0);
if (tasks[0] != null)
tasks[0].cancel(true);
And finally my problem:
I found that when I cancel the download, mostly when it's after 50%, there is one last call to onProgressUpdated(progress) AFTER the progressView.setProgress(0) so the download is cancelled but the progress bar is stuck at the last progress instead of going to 0 (When you set a new progress, it animates itself in a very cool way).
I tried to workaround this in various ways, like having a boolean on the AsyncTask to know if it's canceled, a method that sets it to true, and a check of it in onProgressUpdated(progress) of the AsyncTask before calling the onProgressUpdated(progress) of the listener which sets the progress on the view; and I didn't be able to find a solution.

the onProgressUpdated() and progressView.setProgress(0); both run on UI thread, so you can add a boolean check with them.
add a boolean field boolean noMoreProgressUpdate = false
add noMoreProgressUpdate = true after progressView.setProgress(0);
change
public void onProgressUpdated(int progress) {
progressView.setProgress(progress);
}
to
`
public void onProgressUpdated(int progress) {
if(!noMoreProgressUpdate) {
progressView.setProgress(progress);
}
}
`

I'd use
onPreExecute() {
//do progress bar here
}
and then in onPostExecute()
onPostExecute(String result) {
//dismiss progress bar before anything else
}

Monitoring BufferedInputStream download progress

I'm trying to download a file using an AsyncTask on Android. I want to display a ProgressDialog which should have a progress bar to show the status of the download. I'm using the onProgressUpdate() function for that and implemented a call to publishProgress() in my doInBackground() function. However, the progress dialog only pops up after downloading the file. My code:
protected Long doInBackground(URL...urls) {
for (int i = 0; i < urls.length; i++) {
url = urls[i];
try {
URLConnection conn = url.openConnection();
conn.connect();
totalSize = conn.getContentLength();
BufferedInputStream bis = new BufferedInputStream(url.openStream());
FileOutputStream fos = new FileOutputStream(Environment.getExternalStorageDirectory().getPath() + "/forvo_temp.mp3");
BufferedOutputStream bos = new BufferedOutputStream(fos,1024);
byte [] data = new byte[1024];
int x=0; int c=0;
while((x=bis.read(data,0,1024))>=0){
bos.write(data,0,x);
c += 1024;
publishProgress(c);
}
} catch (Exception e) {
e.printStackTrace();
}
}
return 0L; // Don't know what to do with this
}
protected void onProgressUpdate(Integer...args) {
pd = ProgressDialog.show(context, "Downloading...", "Downloading...", true, false);
pd.setProgress(args[0] / totalSize);
}
I guess the whole file is downloaded when I call new BufferedInputStream(url.openStream()). How can I monitor the download progress?

Wrap URL input stream with you own InputStream that just reads bytes and "monitors" the status, e.g. sends notifications.
It is simple: InputStream is an abstract class with only one abstract method:
public abstract int read() throws IOException;
In your case it should read bytes from stream that it wraps.
public class NotifcationInputStream extends InputStream {
private InputStream in;
private int count;
private Collection<ByteListener> listeners = new ArrayList<ByteListener>();
NotificationInputStream(InputStream in) {
this.in = in;
}
public int read() throws IOException {
int b = in.read();
byteReceived(b);
return b;
}
public void addListener(ByteListener listener) {
listeners.add(listener);
}
private void byteReceived(int b) {
for (ByteListener l : listeners) {
l.byteReceived(b, ++count);
}
}
}
public interface ByteListener extends EventListener {
public void byteReceived(int b, int count);
}
The problem here is how to show the process bar: you have to know total number of bytes. You can get it from HTTP header content-length if your resource is static. Otherwise you need appropriate server support or heuristics.

This code is useful showing download items totol size and downloaded size.
private static final int DOWNLOAD_ONPROGRESS = 1;
#Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DOWNLOAD_ONPROGRESS:
progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Downloading latest ...");
progressDialog.setCancelable(true);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
try {
progressDialog.show();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return progressDialog;
default:
return null;
}
}
You can use AsyncTask for downloading the version in background.
private class DownLoad extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
logger.info("LoadDataAsync onPreExecute");
showDialog(DOWNLOAD_ONPROGRESS);
}
#Override
protected String doInBackground(String... aurl) {
int count = 0;
try {
URL url = new URL(aurl[0]);
URLConnection urlConnection = url.openConnection();
urlConnection.connect();
int contentlength = urlConnection.getContentLength();
progressDialog.setMax(contentlength);
String PATH = "";
File file = null;
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)) {
PATH = Environment.getExternalStorageDirectory()
+ "/download/";
file = new File(PATH);
file.mkdirs();
File outputFile = new File(file, "telfaz.apk");
OutputStream fos = new FileOutputStream(outputFile);
InputStream is = new BufferedInputStream(url.openStream());
byte[] buffer = new byte[1024];
long len1 = 0;
while ((count = is.read(buffer)) != -1
&& !downLoad.isCancelled()) {
len1 += count;
publishProgress("" + len1);
fos.write(buffer, 0, count);
}
fos.flush();
fos.close();
is.close();
}
logger.info("Success -> file downloaded succesfully. returning 'success' code");
return Util.APK_DOWNLOAD_SUCCESS;
} catch (IOException e) {
logger.error("Exception in update process : "
+ Util.getStackTrace(e));
}
logger.info("Failed -> file download failed. returning 'error' code");
return Util.APK_DOWNLOAD_FAILED;
}
#Override
protected void onPostExecute(String result) {
logger.info("on DownLoad onPostExecute. result : " + result);
progressDialog.dismiss();
removeDialog(DOWNLOAD_ONPROGRESS);
if (result.equalsIgnoreCase(Util.APK_DOWNLOAD_SUCCESS)) {
Update();
} else {
Toast.makeText(DownloadAllContentsActivity.this,
getString(R.string.updateApplicationFailed),
Toast.LENGTH_LONG).show();
loadDataAsync.execute();
}
}
#Override
protected void onProgressUpdate(String... values) {
if (values != null && values.length > 0) {
progressDialog.setProgress(Integer.parseInt(values[0]));
}
}
}