For example I am downloading a file from server, in between the connectivity is lost at that point in time my download was 30%, after some time I got a connection .Now I want to start a downloading from 30%, not from 0%.How to achieve this asynctask android.
If any alternative is there please, let me know.???
You need to first figure out how many bytes you have actually downloaded. I suggest saving your file with an different name when it's being downloaded so you can can easily see if you have an unfinished download.
Check the status of you file first to see how much you have downloaded.
private long isIncomplete(){
File from = new File(dir,fileName+"-incomplete");
if(from.exists()){
Log.d("status","download is incomplete, filesize:" + from.length());
return from.length();
}
return 0;
}
Then when creating your http request you can tell the server from what point to serve you the file so that you can resume download.
long downloaded = isIncomplete();
urlConnection.setRequestProperty("Range", "bytes="+(downloaded)+"-");
See this class that I wrote a few years back for a complete implementation.
Update: I suggest you do not use the Shared Preferences for this. SSOT states that you get the info from only one source not more hence reading the progress from the downloaded file.
You can store the destination file path in sharedpreferences and you can do the following code.
HttpURLConnection connection = (HttpURLConnection) url.openConnection();//Opening the url
File file=new File(DESTINATION_PATH);
if(file.exists()){ //check if file exists
downloaded = (int) file.length();
connection.setRequestProperty("Range", "bytes="+(file.length())+"-");
}
else{
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
}
connection.setDoInput(true);
connection.setDoOutput(true);
pBar.setMax(connection.getContentLength());
in = new BufferedInputStream(connection.getInputStream());
fos=(downloaded==0)? new FileOutputStream(DESTINATION_PATH): new FileOutputStream(DESTINATION_PATH,true);
bout = new BufferedOutputStream(fos, 1024);
byte[] data = new byte[1024];
int x = 0;
while ((x = in.read(data, 0, 1024)) >= 0) {
bout.write(data, 0, x);
downloaded += x;
pBar.setProgress(downloaded);
}
Related
I want to download all the images I have on server in the array string of Url one by one so that I may do not have to download a zip file of images from the server and to unzip after downloading it.
So I thought to download the images one by one and to show the download status in the progress bar. But I am extremely failed in it. An Idea came into my mind to make the string array of the Url and to use the For loop to download but it is downloading the last image of the String array and decline or pass all other images in the array . I think I have got the idea that what is going on but I have know Idea what would be the solution then.
What I have done So far
protected Void doInBackground(Void... arg0) {
try {
//set the download URL, a url that points to a file on the internet
//this is the file to be downloaded
String [] imageUrl = {"http://www.androidbegin.com/tutorial/flag/india.png","http://www.androidbegin.com/tutorial/flag/pakistan.png"
,"http://www.androidbegin.com/tutorial/flag/china.png","http://www.androidbegin.com/tutorial/flag/unitedstates.png"};
URL url;
HttpURLConnection urlConnection = null;
for(int i=0;i<imageUrl.length;i++){
url = new URL(imageUrl[i]);
//create the new connection
urlConnection = (HttpURLConnection) url.openConnection();
//set up some things on the connection
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//and connect!
urlConnection.connect();
}
File storagePath = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "Test");
storagePath.mkdirs();
String finalName = Long.toString(System.currentTimeMillis());
File myImage = new File(storagePath, finalName + ".png");
//this will be used to write the downloaded data into the file we created
FileOutputStream fileOutput = new FileOutputStream(myImage);
//this will be used in reading the data from the internet
InputStream inputStream = urlConnection.getInputStream();
//this is the total size of the file
int totalSize = urlConnection.getContentLength();
//variable to store total downloaded bytes
int downloadedSize = 0;
//create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0; //used to store a temporary size of the buffer
//now, read through the input buffer and write the contents to the file
while ((bufferLength = inputStream.read(buffer)) > 0) {
//add the data in the buffer to the file in the file output stream (the file on the sd card
fileOutput.write(buffer, 0, bufferLength);
//add up the size so we know how much is downloaded
downloadedSize += bufferLength;
//this is where you would do something to report the prgress, like this maybe
// updateProgress(downloadedSize, totalSize);
}
//close the output stream when done
fileOutput.close();
//catch some possible errors...
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// see http://androidsnippets.com/download-an-http-file-to-sdcard-with-progress-notification
return null;
}
** What I want :**
Download all the images one by one.
After downloading one Image it should get save in the device and update the progress status.
Please show me some source code rather then giving me just Idea how to do it. And little source code and complete work around on this would be appreciated.
the saving image code should be taken inside for loop. as this code is outside of for loop only your last image is getting saved as at the end of for loop last url is used.
working on my first real android app and one part of it is a download manager.
it must download video files that the app uses to teach people Gaelic.
it works fine on all but 3 files, it downloads bigger files and smaller files. but will not download colours.mp4 1.86MB, weekdays 1.53 MB or numbers 1.99 MB all the files between 1MB and 2MB.
it will just stop at the end of the download loop no errors for a few minutes just looking like its waiting to continue downloading then it will give an error "unexpected end of stream"
can anyone suggest what the problem could be please?
I have crated the same app for the iPhone and that app has not got the same problem with these files.
this is the download loop called from inside an asynctask.
protected void download(String where, String file){
try {
//makes output file
OutputStream output = new FileOutputStream(getFilesDir()
.getAbsolutePath() + "/vidos/" +file);
int count=0;
//gets url to download from
URL url = new URL(where);
URLConnection conection = url.openConnection();
conection.connect();
//gets the length of the file to work out percent downloaded
int lengthOfFile = conection.getContentLength();
InputStream input = null;
Log.v("downloading", String.valueOf(showprg));
input = new BufferedInputStream(url.openStream());
byte data[] = new byte[lengthOfFile];
long total = 0;
Log.v("downloading", "size: " + String.valueOf(downloading));
while ((count = input.read(data)) > 0 && downloading) {
total += count;
publishProgress(String
.valueOf((int) ((total * 100) / lengthOfFile)));
output.write(data, 0, count);
//this is where it brakes
};
Log.v("publishProgress", "done");
output.flush();
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
}
I changed my URLConnection to a HttpURLConnection and removed the BufferedInputStream and now it downloads without problem.
thanks to Harshit Rathi for his link to Cristian's post
I use below code to download file:
URL u = new URL(one.getSrcPath());
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.setReadTimeout(10000);
c.connect();
int lenghtOfFile = c.getContentLength();
FileOutputStream f = new FileOutputStream(new File(Environment.getExternalStorageDirectory() + "/" + SavePath, FileName);
InputStream in = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
int finishbyte = 0;
long total = 0;
while((len1 = in.read(buffer)) > 0) {
total += len1; //total = total + len1
f.write(buffer, 0, len1);
finishbyte++;
}
f.close();
I have two problems:
First, why my download task download fail very high frequency?
Second, if I want my download task resume from break point.
I have get the finishbyte.
How can I modify?
finishbyte both does not represent any information (except the number of calls to the read method, but certainly not the size of the downloaded file), and is not relevant, since you have written to a file and can use the File.length() method to know how much you got so far.
To resume a download:
Open your file, check the size, request a range using the http header that is:
Range: <file.length()>-
(example, if you have downloaded 234 bytes:
Range: 234-
If the response code from the server is 206 Partial Content, you can append to your file, if it is 200, you have to overwrite your file (content have changed or Range is not supported)
To start downloading a file starting with finishbyte position, you will have to use the Range HTTP header. As for the failed downloads problem, it's probably a network issue or phone sleep issue, in which case you should check out the wifi lock
I have this snippet of code in which I want to handle the downlaod of the file being clicked:
else if (url.startsWith("http://rapahh.com/songs2/Music%20Promotion/Download/")) {
}
return false;
Although I have no idea how to handle downloads in Android, so does anyone have a snippet of code I can use to download the file in the background to a folder.. the download folder is fine. Thanks.
What version of android are you building for?
Starting with API lvl 9 there is the DownloadManager that can handle this for you. If at all possible you should use the DownloadManager, because it will automatically handle network interuptions and resume the downloads for you.
If you are aiming for lower API lvl than that you'll have to make the download code yourself. You'll have an inputStream coming from your web source and an outputStream going to your local file and you will loop through the inputStream writing chunks until there are none left.
Something like this:
try {
URL url = new URL(URL); //URL of the video
//Set our file to the correct path and name.
File file = new File(PATH + fileName);
//keep the start time so we can display how long it took to the Log.
long startTime = System.currentTimeMillis();
Log.d(myTag, "download begining");
//Log.d(myTag, "download url:" + url);
Log.d(myTag, "downloaded file name:" + fileName);
/* Open a connection to that URL. */
URLConnection ucon = url.openConnection();
// this will be useful so that you can show a tipical 0-100% progress bar
int lenghtOfFile = ucon.getContentLength();
Log.i(myTag, "Opened Connection");
/************************************************
* Define InputStreams to read from the URLConnection.
************************************************/
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
Log.i(myTag, "Got InputStream and BufferedInputStream");
/************************************************
* Define OutputStreams to write to our file.
************************************************/
FileOutputStream fos = new FileOutputStream(file);
BufferedOutputStream bos = new BufferedOutputStream(fos);
Log.i(myTag, "Got FileOutputStream and BufferedOutputStream");
/************************************************
* Start reading the and writing our file.
************************************************/
byte data[] = new byte[1024];
long total = 0;
int count;
//loop and read the current chunk
while ((count = bis.read(data)) != -1) {
//Post our progress update back to the UI thread
postProgress((int)(total*100/lenghtOfFile));
//write this chunk
total += count;
bos.write(data, 0, count);
}
//Have to call flush or the video file can get corrupted and won't play correctly.
bos.flush();
bos.close();
Log.d(myTag, "download ready in "
+ ((System.currentTimeMillis() - startTime))
+ " milisec");
} catch (IOException e) {
Log.d(myTag, "Error: " + e);
}
You'll need to implement the postProgress(int progress) method to do whatever is appropriate for your application to inform the user of what percentage complete the download is.
Edit:
you can comment out the logs to get it to work. I leave them on while I am debugging though to make the process easier. Log statements such as Log.i(String tag, String text)
are similar to System.out.println(String txt) The difference is that these statements are printed into the log file ( which you can see in the DDMS perspective in eclipse) And they have an additional parameter called "tag" you can pass it whatever string you like and this string will show up along side of your text in the log file. You can also filter the log output basted on these tags in the DDMS perspective. It is common practice to declare your tag as a static String so that you can just use that reference to it for all of your log statements and you are guaranteed to always have the same tag. So if you add something like this to your class it should fix your error:
final static String myTag = "NameOfYourActivity";
I anm new to android.I am making an application in which i want to display the size of file that is downloaded from server.
Is there any way to display that how much we have downloaded?
Plz
if anyone can help out.
Thanks
I hope you are storing the the data whcih you get from server in a file in any particular location. So create a file passinb the absolute path of the location. use length() method to get the file size.
In this way you can get how much data you have downloaded from server
File f = new File("absolutepath");
if(f.exists()){
f.length()
}
Thanks
Deepak
Hey there. You may use the code below or preferred in async task, where in onProgressUpdate method you may check the size from the input source variable.
URL u = new URL("http://www.java2s.com/binary.dat");
URLConnection uc = u.openConnection();
String contentType = uc.getContentType();
int contentLength = uc.getContentLength();
if (contentType.startsWith("text/") || contentLength == -1) {
throw new IOException("This is not a binary file.");
}
InputStream raw = uc.getInputStream();
InputStream in = new BufferedInputStream(raw);
byte[] data = new byte[contentLength];
int bytesRead = 0;
int offset = 0;
while (offset < contentLength) {
bytesRead = in.read(data, offset, data.length - offset);
if (bytesRead == -1)
break;
offset += bytesRead;
}
in.close();
Just go through the documentation below, which explains async task. In its progress update u can check size of input sorce file.
If you want to show this to UI then use progress dialog.
ProgressDialog