Develop Reference

Can't download any file with AsyncTask on mobile network

I have an AsyncTask method for downloading a JSON file. After downloading, on postExecute I populate my listview.
My problem is this method will not work when I'm connected to mobile network. I've tried it with different phones, or it will be stuck in ProgressDialog spinner, or it will show nothing after dismissing ProgressDialog on postExecute.
But when the phone is connected to the wifi network it's fine and I'll get my result.
Method
public class JsonDownloader extends AsyncTask<String, Integer, String> {
private PowerManager.WakeLock mWakeLock;
private FileOutputStream out = null;
private File filename = null;
#Override
protected void onPreExecute() {
super.onPreExecute();
PowerManager pm = (PowerManager) getActivity().getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,getClass().getName());
mWakeLock.acquire();
mProgressDialog = new ProgressDialog(getActivity());
mProgressDialog.setTitle("Preparing List...");
mProgressDialog.setMessage("Please wait while list is populating...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.setCancelable(true);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgressDialog.setMax(100);
mProgressDialog.setProgress(100);
mProgressDialog.show();
mProgressDialog.setContentView(R.layout.custom_progressdialog);
ProgressBar progressbar=(ProgressBar)mProgressDialog.findViewById(R.id.pbar);
progressbar.getIndeterminateDrawable().setColorFilter(Color.parseColor("#FF4081"), android.graphics.PorterDuff.Mode.SRC_IN);
}
#Override
protected String doInBackground(String... image_urls) {
InputStream input = null;
HttpURLConnection connection = null;
try {
URL url = new URL(image_urls[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return "Server returned HTTP " + connection.getResponseCode()
+ " " + connection.getResponseMessage();
}
int fileLength = connection.getContentLength();
input = connection.getInputStream();
Log.i("in save()", "after mkdir");
filename = new File(path+offlineJsonFileName +".txt");
Log.i("in save()", "after file");
out = new FileOutputStream(filename);
Log.i("in save()", "after outputstream");
out.flush();
out.close();
Log.i("in save()", "after outputstream closed");
out = new FileOutputStream(filename);
byte data[] = new byte[4096];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
if (isCancelled()) {
input.close();
return null;
}
total += count;
if (fileLength > 0) // only if total length is known
publishProgress((int) (total * 100 / fileLength));
out.write(data, 0, count);
}
} catch (Exception e) {
return e.toString();
} finally {
try {
if (out != null)
out.close();
if (input != null)
input.close();
} catch (IOException ignored) {
}
if (connection != null)
connection.disconnect();
}
return null;
}
#Override
protected void onProgressUpdate(Integer... progress) {
super.onProgressUpdate(progress);
mProgressDialog.setIndeterminate(false);
mProgressDialog.setMax(100);
mProgressDialog.setProgress(progress[0]);
}
#Override
protected void onPostExecute(String args) {
mWakeLock.release();
mProgressDialog.dismiss();
ReadFile();
}
}
And I execute it like this:
jsonDownloader = new JsonDownloader();
jsonDownloader.execute(url);

out.flush();
out.close();
Log.i("in save()", "after outputstream closed");
out = new FileOutputStream(filename);
Remove that all. Why close and reopen an output stream?
After you are done with the writing do a flush().

I made it work by the following
class JsonDownloaderNew extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
System.out.println("Starting download");
mProgressDialog = new ProgressDialog(activity);
mProgressDialog.setTitle("Preparing List...");
mProgressDialog.setMessage("Please wait while list is populating...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.setCancelable(false);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgressDialog.setMax(100);
mProgressDialog.setProgress(100);
mProgressDialog.show();
mProgressDialog.setContentView(R.layout.custom_progressdialog);
ProgressBar progressbar=(ProgressBar)mProgressDialog.findViewById(R.id.pbar);
progressbar.getIndeterminateDrawable().setColorFilter(Color.parseColor("#FF4081"), android.graphics.PorterDuff.Mode.SRC_IN);
}
#Override
protected String doInBackground(String... f_url) {
int count;
try {
System.out.println("Downloading");
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// getting file length
int lenghtOfFile = conection.getContentLength();
// input stream to read file - with 8k buffer
InputStream input = new BufferedInputStream(url.openStream(), 8192);
// Output stream to write file
File filename = new File(path+offlineJsonFileName +".txt");
OutputStream output = new FileOutputStream(filename);
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
// 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;
}
#Override
protected void onPostExecute(String file_url) {
System.out.println("Downloaded");
mProgressDialog.dismiss();
ReadFile();
}
}

How to hide the browser when downloading files from online

I am trying to download a file from an online source of mine. The issue I am having is that the browser window keeps appearing as it load into the download server. Is there some way that I may be able to hide this? I already have this code below in the doInBackground portion of an AsyncTask, but cant seem to get it to hide the browser bar. Here is my code at this point:
private class getErDone extends AsyncTask<Void, Void, Void>{
#Override
protected void onPreExecute() {
ProgressDialog progressDialog = new ProgressDialog(getApplicationContext());
progressDialog.setTitle("Downloading Software");
progressDialog.setMessage("Now Updating, DO NOT TURN OFF DEVICE");
progressDialog.setCancelable(false);
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... params) {
try{
Intent goToMarket = new Intent(Intent.ACTION_VIEW)
.setData(Uri.parse("http://mydownloadlink.com/myfile?dl=1"));
//**Note** As convincing as it seems, this is not the real download link
startActivity(goToMarket);
}catch (UnknownError e){
e.printStackTrace();
}
/*catch (MalformedURLException e){
e.printStackTrace();
}catch (IOException t){
t.printStackTrace();
}*/
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
}
Thanks everyone!

here is sample from my code, download without browser:
private TextView mFileDownloadProgressBarPercent;
private ProgressBar mFileDownloadProgressBar;
private Runnable mFileExecutionTaskAfterDownload;
public String fileDownloadedResultPath;
and asynctask:
class DownloadFileFromURL extends AsyncTask<String, String, String> {
// Before starting background thread
// Show Progress Bar Dialog
#Override
protected void onPreExecute() {
super.onPreExecute();
if(mFileDownloadProgressBar != null)
mFileDownloadProgressBar.setVisibility(View.VISIBLE);
if(mFileDownloadProgressBarPercent != null)
mFileDownloadProgressBarPercent.setVisibility(View.VISIBLE);
}
// Downloading file in background thread
#Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// getting file length
int lenghtOfFile = conection.getContentLength();
// input stream to read file - with 8k buffer
InputStream input = new BufferedInputStream(url.openStream(), 8192);
String extStorageDirectory = Environment.getExternalStorageDirectory()
.toString();
File folder = new File(extStorageDirectory, "pdf"); // for example we are downloading pdf's so store in pdf dir.
folder.mkdir();
File subFolder = new File(extStorageDirectory+"/pdf", "fileId"); // here you can place files by id of category etc..
subFolder.mkdir();
String fileName = url.toString().substring(url.toString().lastIndexOf("/")+1);
fileDownloadedResultPath = subFolder + "/" + fileName;
// Output stream to write file
OutputStream output = new FileOutputStream(subFolder + "/" + fileName);
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
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) {
if(mFileDownloadProgressBar != null)
mFileDownloadProgressBar.setProgress(Integer.parseInt(progress[0]));
if(mFileDownloadProgressBarPercent != null)
mFileDownloadProgressBarPercent.setText(mContext.getString(R.string.downloading_file) + " " + String.format("%s%%",Integer.parseInt(progress[0])+""));
}
#Override
protected void onPostExecute(String file_url) {
if(mFileDownloadProgressBar != null)
mFileDownloadProgressBar.setVisibility(View.GONE);
if(mFileDownloadProgressBarPercent != null)
mFileDownloadProgressBarPercent.setVisibility(View.GONE);
if(mFileExecutionTaskAfterDownload != null)
mFileExecutionTaskAfterDownload.run();
}
}

How to check if AsyncTask has downloaded one item of a set

My app is a media player, it plays media by downloading the appropriate files from the Internet. I am using AsyncTask to do this, however the task takes longer to execute when multiple files need to be downloaded which results in a media player delay.
The desired behavior is to start playing a file after it has been downloaded while continuing to download any other files.
My code is as follows:
public class DownloadTask extends AsyncTask<String, Integer, String> {
private Context context;
private PowerManager.WakeLock mWakeLock;
private String folder;
private ProgressDialog mProgressDialog;
private int noOfURLs;
private int noUrlLoad;
public DownloadTask(Context context, String folder, ProgressDialog mProgressDialog) {
this.context = context;
this.folder = folder;
}
#Override
protected String doInBackground(String... sUrl) {
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
noOfURLs = sUrl.length;
for (int i = 0; i < sUrl.length; i++) {
URL url = new URL(sUrl[i]);
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 "Máy chủ trả về 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(Environment.getExternalStorageDirectory() + "/" + folder + "/File" + (i + 1) + "." + sUrl[i].charAt(sUrl[i].length() - 3) + sUrl[i].charAt(sUrl[i].length() - 2) + sUrl[i].charAt(sUrl[i].length() - 1));
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);
}
noUrlLoad++;
} 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;
}
#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();
}
#Override
protected void onProgressUpdate(Integer... progress) {
super.onProgressUpdate(progress);
// if we get here, length is known, now set indeterminate to false
}
#Override
protected void onPostExecute(String result) {
mWakeLock.release();
mProgressDialog.dismiss();
if (result != null)
Toast.makeText(context, context.getString(R.string.error) + result, Toast.LENGTH_LONG).show();
}
}

Inside your doInBackground method, call publishProgress(Integer) to send your updates to the UI thread. This will trigger the onProgressUpdate method to be called, and you'll be able to see when the first download has finished.
http://developer.android.com/reference/android/os/AsyncTask.html#publishProgress(Progress...)

Android show the percentage progress of RESTful API

I am trying to call an Restful api using following code. Now I want to show the progress(% of download). Is it at all possible? If, what change in code is needed for that?
BufferedReader reader=null;
try{
URL mUrl = new URL("http://dev.amazaws.com/formservice/rest/v1/registrationreports/registrationsbyproduct/132866/");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write( data );
writer.flush();
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null)
{
sb.append(line);
}
String res = sb.toString();
}catch(Exception ex){
}finally{
try{
reader.close();
}catch(Exception ex) {}
}

Try this code, i have implemented this code in one of my application! You can get the idea how to show the percentage! and well This code actually download the JSON from server and saves it on mobile device.
public class LoginActivity extends Activity {
private ProgressDialog prgDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login_layout);
}
// Button Click function, on which you want to make restApi call
public void buttonClicked(View view){
new PrefetchData().execute();
}
private class PrefetchData extends AsyncTask<Void, Integer, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// before making http calls
prgDialog = new ProgressDialog(LoginActivity.this);
prgDialog.setMessage("Downloading Data. Please wait...");
prgDialog.setIndeterminate(false);
prgDialog.setMax(100);
prgDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
prgDialog.setCancelable(false);
prgDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
URL url = new URL("http://xyz/testJSON");
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) {
// Show ERROR
}
int fileLength = connection.getContentLength();
input = connection.getInputStream();
String extPath = Environment.getExternalStorageDirectory() + "/" + FILE_PATH;
// Environment.
File file = new File(extPath);
if(!file.exists()){
file.createNewFile();
}
output = new FileOutputStream(extPath);
byte data[] = new byte[4096];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
total += count;
if (fileLength > 0){
// only if total length is known
// publishing the progress....
publishProgress((int) (total * 100 / fileLength));
}
output.write(data, 0, count);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (output != null)
output.close();
if (input != null)
input.close();
} catch (IOException ignored) {
}
if (connection != null)
connection.disconnect();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// After completing http call
// will close this activity and lauch main activity
Intent i = new Intent(LoginActivity.this, MainActivity.class);
startActivity(i);
// close this activity
finish();
}
//Update the progress
#Override
protected void onProgressUpdate(Integer... values)
{
prgDialog.setProgress(values[0]);
}
}

As stated in this question you most often wont know the size of the stream in advance https://stackoverflow.com/a/1119346/2122552
The stated answer also links to an api to get Filesizes. But with a RESTful API you usually dont know the exact size of the Inputstream.
But, however, if you know the size you can break it down to use 100 as 100% and calculate the progress as (downloadedBytes/fileSizeInBytes * 100). Otherwise just use an indeterminate ProgressBar.
You can check the case and make the progressbar indeterminate when you dont know the size of the answer, and otherwise calculate the progress and update it like shown in the official documentation

Multiple files download android

I want to download some files from url to refresh my app but I don´t know what is the best way to do this. I have this code to download one file but when I download more than one sometimes gives me an error. Is it possible to do the download in background without using Android Activity? Thank you
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,"Error en la descarga: "+result, Toast.LENGTH_LONG).show();
else
Toast.makeText(context,"Programa actualizado correctamente", Toast.LENGTH_LONG).show();
}
#Override
protected String doInBackground(String... sUrl) {
InputStream input = 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();
fOut = openFileOutput("example.json",MODE_PRIVATE);
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));
fOut.write(data, 0, count);
}
} catch (Exception e) {
return e.toString();
} finally {
try {
if (fOut != null)
fOut.close();
if (input != null)
input.close();
} catch (IOException ignored) {
}
if (connection != null)
connection.disconnect();
}
return null;
}
}
and I call to this task with:
downloadTask.execute("myurl");

private class DownloadAsynkTask extends AsyncTask<String, Void, Integer> {
#Override
protected void onPreExecute() {
// progress dialog
}
#Override
protected Integer doInBackground(String... urls) {
HttpURLConnection connection = null;
InputStream is = null;
for (int i=0; i< urls.length; i++) {
try {
URL url = new URL(urls[i]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return connection.getResponseCode();
} else {
is = connection.getInputStream();
}
// do something whit url data (add it to list maybe)
if (connection != null) {
connection.disconnect();
}
if (is != null) {
is.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
return 1;
}
#Override
protected void onPostExecute(Integer result) {
if (result == 1) {
// OK
} else {
}
}
}
and call it whit String[] urls
new DownloadAsynkTask().execute(urls);