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

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:

Related

Download Image from Url and covert into byte array - android

I'm receiving URL of images and other data from API and showing images into recyclerview, I want to store images in room database in a byte array format, but I'm getting an error while converting image URL to a byte array. My app is crashing at url.openstream();.
private byte[] getByteArrayImage(String imageUrl) {
URL url = null;
try {
url = new URL(imageUrl);
} catch (MalformedURLException e) {
e.printStackTrace();
}
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try {
byte[] chunk = new byte[4096];
int bytesRead;
InputStream stream = url.openStream();
while ((bytesRead = stream.read(chunk)) > 0) {
outputStream.write(chunk, 0, bytesRead);
}
url.openStream().close();
} catch (IOException e) {
e.printStackTrace();
return null;
}
return outputStream.toByteArray();
}
There are a couple of problems with your code:
As already noted in a comment, you call openStream() twice.
If an exception occurs, close() won't be called in your code. Use try-with-resources instead.
Propagate exceptions to the caller. The caller will generally want to know the exception message.
Don't ever use printStackTrace(). This is the worst way to report errors.
After the first printStackTrace(), you continue with a null URI, which will cause a NullPointerException.
The method should be static.
Here's how I would write this:
private static byte[] getImageBytes(String imageUrl) throws IOException
{
URL url = new URL(imageUrl);
ByteArrayOutputStream output = new ByteArrayOutputStream();
try (InputStream stream = url.openStream())
{
byte[] buffer = new byte[4096];
while (true)
{
int bytesRead = stream.read(buffer);
if (bytesRead < 0) { break; }
output.write(buffer, 0, bytesRead);
}
}
return output.toByteArray();
}
I recommend below pseudo code to read data from URL:
Thread t = new Thread(new Runnable()
{
#Override
public void run()
{
try
{
URL url = new URL("you'r address");
URLConnection connection = url.openConnection();
InputStream is = connection.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
StringBuffer sb = new StringBuffer();
int r;
while((r = isr.read()) != -1)
{
sb.append(r);
}
byte buffer[] = sb.toString().getBytes();
}
catch (MalformedURLException e)
{
e.printStackTrace();
Log.i("tag" , "MalformedURLException"+e.getMessage());
}
catch (IOException e)
{
e.printStackTrace();
Log.i("tag" , "IOException"+e.getMessage());
}
}
});
t.start();

simple http server for sending files in android via wifi

I am developing application which will send some files from one android device to an other device. One device will create a hot spot and will use the web browser to receive some files from the other device which will connect to the hot spot using WiFi. I do not known to much about HTTP. I have created simple sever in the sending device. The receiving device will connect to the server with its web browser. When i write the (IP:port number ) in the browser, it say "starting download" but the download does not finished. in the sending device i get IOException: sendto failed EPIPE (Broken pipe) .
my code is
boolean sending_done = false;
while (! sending_done)
{
Socket socket = null;
try
{
socket = serverSocket.accept();
OutputStream outputStream = socket.getOutputStream();
outputStream.write("HTTP/1.1 200 OK\r\n".getBytes());
outputStream.write("Content-Type: application/zip\r\n".getBytes());
outputStream.write("Content-Disposition: attachment; filename=files.zip\r\n".getBytes());
outputStream.write("Content-Encoding: gzip\r\n".getBytes());
outputStream.write("Transfer-Encoding: chunked\r\n".getBytes());
outputStream.write("\r\n".getBytes());
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
ZipOutputStream zipOutputStream = new ZipOutputStream(bufferedOutputStream);
zipOutputStream.setLevel(ZipOutputStream.STORED);
sendFiles(zipOutputStream, to_send_files_array_list);
byte[] CRLF ="\r\n".getBytes();
writ_header(0, zipOutputStream, CRLF);
zipOutputStream.write(CRLF, 0, CRLF.length);
zipOutputStream.finish();
zipOutputStream.flush();
zipOutputStream.close();
sending_done = true;
}
catch (IOException e)
{
e.printStackTrace();
display_toast(e.toString());
}
finally
{
try
{
if (socket != null)
{
socket.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void sendFiles(ZipOutputStream zipOutputStream, ArrayList<File> filesToSend)
{
byte[] CRLF ="\r\n".getBytes();
for(File file: filesToSend)
{
BufferedInputStream bufferedInputStream = null;
ZipEntry zipEntry = null;
try
{
FileInputStream fileInputStream = new FileInputStream(file);
bufferedInputStream = new BufferedInputStream(fileInputStream);
zipEntry = new ZipEntry(file.getName());
zipOutputStream.putNextEntry(zipEntry);
int x;
byte[] buffer = new byte[buffer_size];
while ((x= bufferedInputStream.read(buffer))!= -1)
{
if (x>0)
{
writ_header(x, zipOutputStream, CRLF);
zipOutputStream.write(buffer,0,x);
zipOutputStream.write(CRLF, 0, CRLF.length);
}
}
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
try
{
if (zipEntry != null)
{
zipOutputStream.closeEntry();
}
if (bufferedInputStream != null)
{
bufferedInputStream.close();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
}
private void writ_header(int length, OutputStream outputStream, byte[] CRLF) throws IOException
{
byte[] header = Integer.toHexString(length).getBytes();
outputStream.write(header, 0, header.length);
outputStream.write(CRLF, 0, CRLF.length);
}

Save image Uri as an image

So what I am doing is receiving data as an intent from another app. I am getting the image than attempting to save it
void savefile(Uri sourceuri)
{
String sourceFilename= sourceuri.getPath();
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "PhotoSaver");
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
try {
bis = new BufferedInputStream(new FileInputStream(sourceFilename));
bos = new BufferedOutputStream(new FileOutputStream(mediaStorageDir, false));
byte[] buf = new byte[1024];
bis.read(buf);
do {
bos.write(buf);
} while(bis.read(buf) != -1);
} catch (IOException e) {
} finally {
try {
if (bis != null) bis.close();
if (bos != null) bos.close();
} catch (IOException e) {
}
}
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "PhotoSaver"))));
}
You should be reading till you reach the end of your input stream and finally flush your output stream. Something like this:
// the file is read to the end
while ((value = bis.read()) != -1) {
bos.write(value);
}
// invokes flush to force bytes to be written out to baos
bos.flush();

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();
}
}
}
}

Categories

Resources