Develop Reference

Unsuccessful attempt to create a folder and save mp3 file in android

I have an online music player in which I dedicated a button in order to download the file. There's a "progressDialog" which works fine and shows progress of downloading file and it seems that it's really downloading my file. But after completion there's no folder nor file on my device.
I also added Write External Storage permission in my manifest.
Here's my download class:
public class DownloadTask extends AsyncTask<String, Integer, String> {
#SuppressLint("StaticFieldLeak")
private Context context;
public static ProgressDialog progressBar;
public DownloadTask(Context context) {
this.context = context;
progressBar = new ProgressDialog(context);
progressBar.setMessage("Downloading...");
progressBar.setIndeterminate(true);
progressBar.setCancelable(true);
progressBar.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
}
#Override
protected void onPreExecute() {
super.onPreExecute();
progressBar.show();
}
#Override
protected String doInBackground(String... strings) {
InputStream inputStream = null;
OutputStream outputStream = null;
HttpURLConnection connection = null;
try {
URL url = new URL(strings[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
int fileLength = connection.getContentLength();
inputStream = connection.getInputStream();
fileCache();
outputStream = new FileOutputStream(context.getFilesDir() + "listening"
+ strings[1] + ".mp3");
byte[] data = new byte[4096];
long total = 0;
int count;
while ((count = inputStream.read(data)) != -1) {
total += count;
if (fileLength > 0)
publishProgress((int) (total * 100 / fileLength));
outputStream.write(data, 0, count);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (outputStream != null) {
outputStream.flush();
outputStream.close();
}
if (inputStream != null)
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
if (connection != null)
connection.disconnect();
}
return null;
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
progressBar.setIndeterminate(false);
progressBar.setMax(100);
progressBar.setProgress(values[0]);
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
progressBar.dismiss();
if (s != null) {
Toast.makeText(context, "Error while Downloading", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(context, "Downloaded successfully", Toast.LENGTH_SHORT).show();
}
}
private void fileCache() {
File myDir = new File(context.getFilesDir(), "listening");
if (!myDir.exists()) {
myDir.mkdirs();
}
}
}
And here's my button's function:
DownloadTask downloadTask = new DownloadTask(context);
downloadTask.execute(extra.getString("link"), extra.getString("title"));

Android: access thread from class

I create a file download from web
This code works but after i go to home page , how can access to thread and this listener ?
filedownloader.java
public class FileDownloader {
public static void download(final String downloadPath, final String filepath, final OnProgressDownloadListener listener) {
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
URL url = new URL(downloadPath);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
//connection.setDoOutput(true);
connection.connect();
int fileSize = connection.getContentLength();
File file = new File(filepath);
if (file.exists()) {
file.delete();
}
FileOutputStream outputStream = new FileOutputStream(filepath);
InputStream inputStream = connection.getInputStream();
byte[] buffer = new byte[G.DOWNLOAD_BUFFER_SIZE];
int len = 0;
int downloadedSize = 0;
while ((len = inputStream.read(buffer)) > 0) {
outputStream.write(buffer, 0, len);
downloadedSize += len;
final float downloadPercent = 100.0f * (float) downloadedSize / fileSize;
if (listener != null) {
G.HANDLER.post(new Runnable() {
#Override
public void run() {
listener.onProgressDownload((int) downloadPercent);
}
});
}
}
outputStream.close();
}
catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
}
});
thread.start();
}
}
onprogressdownloadlistener.java
public interface OnProgressDownloadListener {
public void onProgressDownload(int percent);
}
mainactivity.java
OnProgressDownloadListener listener = new OnProgressDownloadListener() {
#Override
public void onProgressDownload(final int percent) {
Log.i(percent + "%");
}
};
FileDownloader.download(dlFile, G.DIR_APP + "/" + fileName, listener);
Percent return size of download
After start download and close page and go to new page , i want to go back to download page. how to access this thread and the listener ?
Thanks

-Hey you can check if percent in main activity's listener object gets "100%" value then you can get you desired output.

How to download sqlite database file from the server in Android?

protected void doDownload(final String urlLink, final String fileName) {
Thread dx = new Thread() {
public void run() {
File root = android.os.Environment.getExternalStorageDirectory();
File dir = new File (root.getAbsolutePath() + "/Content2/");
if(dir.exists()==false) {
dir.mkdirs();
}
//Save the path as a string value
try
{
URL url = new URL(urlLink);
Log.i("FILE_NAME", "File name is "+imageFile);
Log.i("FILE_URLLINK", "File URL is "+url);
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(dir+"/"+imageFile);
byte data[] = new byte[1024];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
total += count;
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
}
catch (Exception e)
{
e.printStackTrace();
Log.i("ERROR ON DOWNLOADING FILES", "ERROR IS" +e);
}
}
};
dx.start();
}
through this, I cannot download the file from the server.
How to solve this problem?

First of all you should use Async-Task.
Here is how you can do this
final DownloadTask downloadTask = new DownloadTask(YourActivity.this);
downloadTask.execute("the url to the file you want to download");
// usually, subclasses of AsyncTask are declared inside the activity class.
// that way, you can easily modify the UI thread from here
private class DownloadTask extends AsyncTask<String, Integer, String> {
private Context context;
public DownloadTask(Context context) {
this.context = context;
}
#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/file_name.extension");
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;
}
} 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 onPostExecute(String result) {
if (result != null)
Toast.makeText(context,"Download error: "+result, Toast.LENGTH_LONG).show();
else
Toast.makeText(context,"File downloaded", Toast.LENGTH_SHORT).show();
}

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);

Download files in android

I am trying to write an application that downloads files in the background. The code crashes when it tries to reenter doInBackground(). This happens when doing is set to false before returning. Code follows -
public class DownloadFile extends AsyncTask<String, Integer, String> {
private boolean doing;
private Activity activity;
private Intent intent;
private File beta;
private File alpha;
public DownloadFile(Activity act, Intent intent) {
this.activity = act;
this.intent = intent;
doing = false;
}
#Override
protected String doInBackground(String... sUrl) {
int fileCount = 0;
if (!download(sUrl[0] + "list.txt",
Environment.getExternalStorageDirectory() + "/alpha/list.txt")){
setDoing(false);
return "Download failed";//list.txt could not be downloaded. return error message.
}
fileCount++;
beta = new File(Environment.getExternalStorageDirectory() + "/beta/");
File betalist = new File(beta + "/list.txt");
alpha = new File(Environment.getExternalStorageDirectory() + "/alpha/");
File alphalist = new File(alpha + "/list.txt");
//verify that the file is changed.
if (alphalist.lastModified() == betalist.lastModified()// these two are
// never equal.
|| alphalist.length() == betalist.length()) { // better to check
// the length of
// the files.
setDoing(false);
return "Nothing to download.";
}
try {
FileReader inAlpha = new FileReader(alphalist);
BufferedReader br = new BufferedReader(inAlpha);
String s;
// read the name of each file in a loop
while ((s = br.readLine()) != null) {
// if(fileExistsInBeta(s)){
// copyFromBetaToAlpha(s);
// continue;
// }
// download the file.
//Url will truncate the trailing / so keep if statement as is.
if (!download(sUrl[0] + s,
Environment.getExternalStorageDirectory() + "/alpha/"
+ s)){
setDoing(false);
return "Failed at " + s;// the given file could not be downloaded. return error.
}
fileCount++;
}
br.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
Log.e("Pankaj", e.getMessage());
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("Pankaj", e.getMessage());
} catch (Exception e) {
Log.e("Pankaj", e.getMessage());
}
Log.d("Pankaj", "Download Done");
activity.overridePendingTransition(0, 0);
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
activity.finish();
Log.d("Pankaj", "MainActivity Killed");
// rename alpha to beta
deleteSubFolders(beta.toString());
beta.delete();
alpha.renameTo(beta);
if (!alpha.exists()) {
alpha.mkdir();
}
File upper = new File(alpha + "/upper/");
if (!upper.exists())
upper.mkdirs();
File lower = new File(alpha + "/lower/");
if (!lower.exists())
lower.mkdirs();
// ConfLoader.getInstance().reload();//to refresh the settings
// restart the activity
activity.overridePendingTransition(0, 0);
activity.startActivity(intent);
Log.d("Pankaj", "MainActivity restarted");
// now reset done status so we can start again.
setDoing(false);
return "Download finished.";// return the status for onPostExecute.
}
private void copyFromBetaToAlpha(String fileName) {
File beta=new File(Environment.getExternalStorageDirectory()+"/beta/"+fileName);
File alpha=new File(Environment.getExternalStorageDirectory()+"/alpha/"+fileName);
try {
FileInputStream fis=new FileInputStream(beta);
FileOutputStream fos=new FileOutputStream(alpha);
byte[] buf=new byte[1024];
int len;
while((len=fis.read(buf))>0){
fos.write(buf, 0, len);
}
fis.close();
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
protected void onPostExecute(String result) {
Toast.makeText(activity, result, Toast.LENGTH_LONG).show();
super.onPostExecute(result);
}
public boolean download(String url, String file) {
boolean successful = true;
try {
URL u = new URL(url);
URLConnection conn = u.openConnection();
conn.connect();
int filelen = conn.getContentLength();
File f = new File(file);
// skip download if lengths are same
// because the file has been downed fully.
if (f.exists() && filelen == f.length()) {
return successful;
}
InputStream is = u.openStream();
DataInputStream dis = new DataInputStream(is);
byte[] buffer = new byte[1024];
int length;
FileOutputStream fos = new FileOutputStream(f);
while ((length = dis.read(buffer)) > 0) {
fos.write(buffer, 0, length);
}
fos.close();
buffer = null;
dis.close();
} catch (MalformedURLException mue) {
Log.e("SYNC getUpdate", "malformed url error", mue);
successful = false;
} catch (IOException ioe) {
Log.e("SYNC getUpdate", "io error", ioe);
successful = false;
} catch (SecurityException se) {
Log.e("SYNC getUpdate", "security error", se);
successful = false;
}
return successful;
}
private void deleteSubFolders(String uri) {
File currentFolder = new File(uri);
File files[] = currentFolder.listFiles();
if (files == null) {
return;
}
for (File f : files) {
if (f.isDirectory()) {
deleteSubFolders(f.toString());
}
// no else, or you'll never get rid of this folder!
f.delete();
}
}
public static int getFilesCount(File file) {
File[] files = file.listFiles();
int count = 0;
for (File f : files)
if (f.isDirectory())
count += getFilesCount(f);
else
count++;
return count;
}
public boolean isDoing() {
return doing;
}
/**
* #param doing
*/
public void setDoing(boolean doing) {
this.doing = doing;
}
private boolean fileExistsInBeta(final String fileName){
boolean exists=false;
File beta=new File(Environment.getExternalStorageDirectory()+"/beta/"+fileName);
if(beta.exists()){
String[] ext=beta.getName().split(".");
String extName=ext[ext.length-1];
exists=(extName!="txt" && extName!="tmr" && extName!="conf");
}
return exists;
}
in the main activity -
public void run() {
if (!downloadFile.isDoing()) {
downloadFile.execute(ConfLoader.getInstance().getListUrl());
downloadFile.setDoing(true);
}
// change the delay so that it covers the time for download and
// doesn't overlap causing multiple downloads jamming the bandwidth.
h.postDelayed(this, 1000);//check after 60 sec.
}
in the onCreate() -
downloadFile = new DownloadFile(this, getIntent());
h = new Handler();
h.postDelayed(this, 1000);
Any help is appreciated. Thanks in advance.
EDIT:
The logcat error is Cannot execute task the task is already running.
Cannot execute task: Task has already been executed(A task can only be executed once).
EDIT:
Is it possible that the error is because I am trying to execute the asynchtask again in run(). Perhaps AsynchTask does not allow re-entry.

Try using this
1. First create a dialogue
#Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DIALOG_DOWNLOAD_PROGRESS:
mProgressDialog = new ProgressDialog(this);
mProgressDialog.setMessage("Downloading file..");
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mProgressDialog.setCancelable(false);
mProgressDialog.show();
return mProgressDialog;
default:
return null;
}
}
The download async task
class DownloadFileAsync extends AsyncTask<String, String, String> {
#SuppressWarnings("deprecation")
#Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(DIALOG_DOWNLOAD_PROGRESS);
}
#Override
protected String doInBackground(String... aurl) {
int count;
File root = android.os.Environment.getExternalStorageDirectory();
//
File dir = new File (root.getAbsolutePath()+"/Downl");
if(dir.exists()==false) {
dir.mkdirs();
}
File file = new File(dir, url.substring(url.lastIndexOf("/")+1)); //name of file
try {
URL url = new URL(aurl[0]);
URLConnection conexion = url.openConnection();
conexion.connect();
int lenghtOfFile = conexion.getContentLength();
Log.d("ANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(file);
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) {}
return null;
}
protected void onProgressUpdate(String... progress) {
Log.d("ANDRO_ASYNC",progress[0]);
mProgressDialog.setProgress(Integer.parseInt(progress[0]));
}
#SuppressWarnings("deprecation")
#Override
protected void onPostExecute(String unused) {
dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
Toast.makeText(DisplayActivity.this,"Successfully downloaded in phone memory.", Toast.LENGTH_SHORT).show();
}
}
Call the async new DownloadFileAsync().execute(url); //pass ur url