Develop Reference

After downloading whole (84M) file from dropbox it turning into 0 bytes

I am downloading a zip file from dropbox. When it keeps downloading I measure the file size and get it is increasing its size with the Below code. It downloads whole 84M and after finishing download it turns into 0 bytes. What wrong am I actually doing?
public static void downloadDropBox(File file) {
String url = "https://www.dropbox.com/sh/jx4b2wvqg8d4ze1/AAA0J3LztkRc6FJ5tKy4dUKha?dl=1";
int bytesRead;
byte[] bytesArray = new byte[1024];
InputStream is = null;
FileOutputStream outputStream = null;
long progres = 0;
try {
URL fileUrl = new URL(url);
HttpURLConnection connection = (HttpURLConnection)fileUrl.openConnection();
connection.connect();
is = connection.getInputStream();
outputStream = new FileOutputStream(file);
while ((bytesRead = is.read(bytesArray, 0, 1024)) != -1) {
outputStream.write(bytesArray, 0, bytesRead);
}
}
} catch (Exception e) {
e.printStackTrace();
}
finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (outputStream != null) {
try {
outputStream.flush();
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
During download file:
After Finishing download file:

Download percentage from file downloading in java

I got this code for downloading my files:
public static void download()
throws MalformedURLException, IOException
{
BufferedInputStream in = null;
FileOutputStream out = null;
try
{
in = new BufferedInputStream(new URL("https://www.dropbox.com/s/1uff8eeujplz4sf/files.zip?dl=1").openStream());
out = new FileOutputStream(System.getProperty("user.home") + "/Adasti/files.zip");
byte data[] = new byte[1024];
int count;
while ((count = in.read(data, 0, 1024)) != -1)
{
out.write(data, 0, count);
}
} catch (MalformedURLException e1)
{
e1.printStackTrace();
} catch (IOException e2)
{
e2.printStackTrace();
} finally
{
if (in != null)
in.close();
if (out != null)
out.close();
}
}
I want to print out the percentage of the download while its downloading. Is this possible with my method and if yes, how will I do it?

You have to get the file size before start the download. Be carefull, not always the server can give you the file size (for sample streaming or some file server). Try this:
/**
*
* #param remotePath
* #param localPath
*/
public static void download(String remotePath, String localPath) {
BufferedInputStream in = null;
FileOutputStream out = null;
try {
URL url = new URL(remotePath);
URLConnection conn = url.openConnection();
int size = conn.getContentLength();
if (size < 0) {
System.out.println("Could not get the file size");
} else {
System.out.println("File size: " + size);
}
in = new BufferedInputStream(url.openStream());
out = new FileOutputStream(localPath);
byte data[] = new byte[1024];
int count;
double sumCount = 0.0;
while ((count = in.read(data, 0, 1024)) != -1) {
out.write(data, 0, count);
sumCount += count;
if (size > 0) {
System.out.println("Percentace: " + (sumCount / size * 100.0) + "%");
}
}
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e2) {
e2.printStackTrace();
} finally {
if (in != null)
try {
in.close();
} catch (IOException e3) {
e3.printStackTrace();
}
if (out != null)
try {
out.close();
} catch (IOException e4) {
e4.printStackTrace();
}
}
}
The call to this method is something like this:
download("https://www.dropbox.com/s/1uff8eeujplz4sf/files.zip?dl=1", System.getProperty("user.home") + "/files.zip");

URL - FileNotFoundException for image file in Android

I'm trying to get a image from particular URL but it throwsFileNotFoundException. If I try to open the url from my browser, i can see the images. Please help. Below is my code. Thanks.
String fileURL = "http://sposter.smartag.my/images/KFC_Voucher.jpg";
String FILENAME = "caldophilus.jpg";
URL u = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
File root = Environment.getExternalStorageDirectory();
FileOutputStream f = new FileOutputStream(new File(root, FILENAME));
InputStream x=c.getInputStream();
int size=x.available();
byte b[]= new byte[size];
x.read(b);
f.write(b);
f.flush();
f.close();

i try this and its work fine. Thanks.
URL url = new URL(fileURL);
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("/sdcard/caldophilus.jpg");
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();

Try this:
BufferedInputStream inputStream = null;
OutputStream out = null;
String fileName = null;
String path = null;
File savedFile = null;
try
{
// Replace your URL here.
URL fileURL = new URL("http://enter.your.url.here");
URLConnection connection = fileURL.openConnection();
connection.connect();
inputStream = new java.io.BufferedInputStream(connection.getInputStream());
// Replace your save path here.
File fileDir = new File("path/to/save");
fileDir.mkdirs();
savedFile = new File("path/to/save", fileName);
out = new FileOutputStream(savedFile);
byte buf[] = new byte[1024];
int len;
long total = 0;
while ((len = inputStream.read(buf)) != -1)
{
total += len;
out.write(buf, 0, len);
}
out.close();
inputStream.close();
}
catch (Exception)
{
}

Try the below code. It should work!
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
public class DownloadManager {
public static void downLoadImage(String imageURL, String destinationFileName) throws IOException {
URL url = new URL(imageURL);
InputStream inputStream = url.openStream();
OutputStream outputStream = new FileOutputStream(destinationFileName);
byte[] byteData = new byte[2048];
int length;
while((length=inputStream.read(byteData))!=-1) {
outputStream.write(byteData, 0, length);
}
inputStream.close();
outputStream.close();
}
public static void main(String[] args) throws IOException {
String imageURL = "http://sposter.smartag.my/images/KFC_Voucher.jpg";
String destinationFileName = "C:/Users/sarath_sivan/Desktop/caldophilus.jpg";
downLoadImage(imageURL, destinationFileName);
}
}

Try this at once -
try {
url = paths[0];
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
int length = connection.getContentLength();
InputStream is = (InputStream) url.getContent();
byte[] imageData = new byte[length];
int buffersize = (int) Math.ceil(length / (double) 100);
int downloaded = 0;
int read;
while (downloaded < length) {
if (length < buffersize) {
read = is.read(imageData, downloaded, length);
} else if ((length - downloaded) <= buffersize) {
read = is.read(imageData, downloaded, length
- downloaded);
} else {
read = is.read(imageData, downloaded, buffersize);
}
downloaded += read;
publishProgress((downloaded * 100) / length);
}
Bitmap bitmap = BitmapFactory.decodeByteArray(imageData, 0,
length);
if (bitmap != null) {
Log.i(TAG, "Bitmap created");
} else {
Log.i(TAG, "Bitmap not created");
}
is.close();
return bitmap;
} catch (MalformedURLException e) {
Log.e(TAG, "Malformed exception: " + e.toString());
} catch (IOException e) {
Log.e(TAG, "IOException: " + e.toString());
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.toString());
}
And, just take a look at here

In ...
FileOutputStream f = new FileOutputStream(new File(root, FILENAME));
Try replacing FILENAME with fileURL.
Also, at which line is the exception thrown? That would help.

String fileURL = "http://sposter.smartag.my/images/KFC_Voucher.jpg";
String FILENAME = "caldophilus.jpg";
URL u = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
//c.setDoOutput(true); =========== remove this;
c.connect();

Error handling for URLConnection

I have this method that downloads .csv files from yahoo finance and saves them locally. It is accessed during a loop so it is downloading many files from a list. However sometimes a symbol is entered incorrectly, no longer exists, or the connection times out. How can I amend this method so that connection time outs are retried and incorrect symbols (meaning the url does not work) are just skipped over without ending the program?
public static void get_file(String symbol){
OutputStream outStream = null;
URLConnection uCon = null;
InputStream is = null;
String finance_url = "http://ichart.finance.yahoo.com/table.csv?s="+symbol;
String destination = "C:/"+symbol+"_table.csv";
try {
URL Url;
byte[] buf;
int ByteRead,ByteWritten=0;
Url= new URL(finance_url);
outStream = new BufferedOutputStream(new FileOutputStream(destination));
uCon = Url.openConnection();
is = uCon.getInputStream();
buf = new byte[size];
while ((ByteRead = is.read(buf)) != -1) {
outStream.write(buf, 0, ByteRead);
ByteWritten += ByteRead;
}
}catch (Exception e) {
System.out.println("Error while downloading "+symbol);
e.printStackTrace();
}finally {
try {
is.close();
outStream.close();
}catch (IOException e) {
e.printStackTrace();
}
}
}

Why not call the method again when an exception is thrown. You can narrow down the exception type to indicate when a retry should be initiated.
public static void get_file(String symbol){
OutputStream outStream = null;
URLConnection uCon = null;
InputStream is = null;
String finance_url = "http://ichart.finance.yahoo.com/table.csv?s="+symbol;
String destination = "C:/"+symbol+"_table.csv";
try {
URL Url;
byte[] buf;
int ByteRead,ByteWritten=0;
Url= new URL(finance_url);
outStream = new BufferedOutputStream(new FileOutputStream(destination));
uCon = Url.openConnection();
is = uCon.getInputStream();
buf = new byte[size];
while ((ByteRead = is.read(buf)) != -1) {
outStream.write(buf, 0, ByteRead);
ByteWritten += ByteRead;
}
}catch (Exception e) {
getFile(symbol);
}finally {
try {
is.close();
outStream.close();
}catch (IOException e) {
e.printStackTrace();
}
}
}

how to resume an interrupted download

I'm trying to download a large file from my Yahoo! web site server which apparently is setup (not by me) to disconnect downloads if they are not completed within 100 seconds. The file is small enough to usually successfully transfer. On the occasions when the data rate is slow and the download gets disconnected, is there a way to resume the URLConnection at the file offset where the disconnection occurred? Here's the code:
// Setup connection.
URL url = new URL(strUrl[0]);
URLConnection cx = url.openConnection();
cx.connect();
// Setup streams and buffers.
int lengthFile = cx.getContentLength();
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(strUrl[1]);
byte data[] = new byte[1024];
// Download file.
for (total=0; (count=input.read(data, 0, 1024)) != -1; total+=count) {
publishProgress((int)(total*100/lengthFile));
output.write(data, 0, count);
Log.d("AsyncDownloadFile", "bytes: " + total);
}
// Close streams.
output.flush();
output.close();
input.close();

Try using a "Range" request header:
// Open connection to URL.
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
// Specify what portion of file to download.
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
// here "downloaded" is the data length already previously downloaded.
// Connect to server.
connection.connect();
Having done that, you can seek at a given point (just before the length of your download data, say X) and start writing the newly downloaded data there. Be sure to use the same value X for the range header.
Details about 14.35.2 Range Retrieval Requests
More details and source code can be found here

Here's an example code that you can use:
import java.io.*;
import java.net.*;
public class HttpUrlDownload {
public static void main(String[] args) {
String strUrl = "http://VRSDLSCEN001:80//DLS//lib//clics.jar";
String DESTINATION_PATH = "clics.jar";
int count = 0;
while (true) {
count++;
if (download(strUrl, DESTINATION_PATH) == true || count > 20) {
break;
}
}
}
public static boolean download(String strUrl, String DESTINATION_PATH) {
BufferedInputStream in = null;
FileOutputStream fos = null;
BufferedOutputStream bout = null;
URLConnection connection = null;
int downloaded = 0;
try {
System.out.println("mark ... download start");
URL url = new URL(strUrl);
connection = url.openConnection();
File file=new File(DESTINATION_PATH);
if(file.exists()){
downloaded = (int) file.length();
}
if (downloaded == 0) {
connection.connect();
}
else {
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
connection.connect();
}
try {
in = new BufferedInputStream(connection.getInputStream());
} catch (IOException e) {
int responseCode = 0;
try {
responseCode = ((HttpURLConnection)connection).getResponseCode();
} catch (IOException e1) {
e1.printStackTrace();
}
if (responseCode == 416) {
return true;
} else {
e.printStackTrace();
return false;
}
}
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);
}
in.close();
bout.flush();
bout.close();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
}
}
if (bout != null) {
try {
bout.close();
} catch (IOException e) {
}
}
if (connection != null) {
((HttpURLConnection)connection).disconnect();
}
}
}
}