I just tried to download a file from a Website, i checked the URL and everything seems to be fine there, but when i try to do it like described it prints out that my update size is -1 Bytes, don't know why this is happening.
If anyone has a solution, i would be glad to here it.
My Code:
private void downloadFile(String link) throws MalformedURLException, IOException
{
URL url = new URL(link);
URLConnection conn = url.openConnection();
InputStream is = conn.getInputStream();
long max = conn.getContentLength();
outText.setText(outText.getText()+"\n"+"Downloding file...\nUpdate Size(compressed): "+max+" Bytes");
System.out.println("Update Size --> " + max + " Bytes");
BufferedOutputStream fOut = new BufferedOutputStream(new FileOutputStream(new File("update.zip")));
byte[] buffer = new byte[32 * 1024];
int bytesRead = 0;
int in = 0;
while ((bytesRead = is.read(buffer)) != -1) {
in += bytesRead;
fOut.write(buffer, 0, bytesRead);
}
fOut.flush();
fOut.close();
is.close();
outText.setText(outText.getText()+"\nDownload Complete!");
}
Big Thanks already :)
The javadoc is your friend:
Returns:
the content length of the resource that this connection's URL references, -1 if the content length is not known, or if the content length is greater than Integer.MAX_VALUE.
(emphasis mine)
Related
I'm trying to download a single file from a web server (http or https) using as few third party libraries as possible.
The method I've come up with is as follows:
private static final int BUFFER_SIZE = 8;
public static boolean download(URL url, File f) throws IOException {
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
FileOutputStream out = new FileOutputStream(f);
BufferedInputStream in = new BufferedInputStream(conn.getInputStream());
byte[] buffer;
long dld = 0, expected = conn.getContentLengthLong(); // TODO expected will be -1 if the content length is unknown
while (true) { // TODO fix endless loop if server timeout
buffer = new byte[BUFFER_SIZE];
int n = in.read(buffer);
if (n == -1) break;
else dld += n;
out.write(buffer);
}
out.close();
System.out.println(dld + "B transmitted to " + f.getAbsolutePath());
return true;
}
However, it does by no means work as intended. I tried to download https://upload.wikimedia.org/wikipedia/commons/6/6d/Rubber_Duck_Florentijn_Hofman_Hong_Kong_2013d.jpg for example, the result was horrifying:
For some reason I was able to view the picture in IrfanView but not in any other viewer, so this is a re saved version.
I tried messing with the buffer size or downloading other images but the results are more or less the same.
If I look at the file, there are entire parts of the content simply replaced with dots:
I'm really lost on this one so thanks for any help :)
The problem occurs when there aren't 8 bytes of data to read. This leaves part of the array filled with zeros, which is why you're seeing so many in your hex editor. The solution is simple: replace out.write(buffer); with out.write(buffer, 0, n);. This tells the FileOutputStream to only read the bytes between indexes 0 and n.
Fixed code:
private static final int BUFFER_SIZE = 8;
public static boolean download(URL url, File f) throws IOException {
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
FileOutputStream out = new FileOutputStream(f);
BufferedInputStream in = new BufferedInputStream(conn.getInputStream());
// We can move the buffer declaration outside the loop
byte[] buffer = new byte[BUFFER_SIZE];
long dld = 0, expected = conn.getContentLengthLong(); // TODO expected will be -1 if the content length is unknown
while (true) {
int n = in.read(buffer);
if (n == -1) break;
else dld += n;
out.write(buffer, 0, n);
}
out.close();
System.out.println(dld + "B transmitted to " + f.getAbsolutePath());
return true;
}
Try something like this to download pictures
public static byte[] download(String param) throws IOException {
InputStream in = null;
ByteArrayOutputStream out = null;
try {
URL url = new URL(param);
HttpURLConnection con = (HttpURLConnection)url.openConnection();
con.setConnectTimeout(120000);
con.setReadTimeout(120000);
con.setRequestMethod("GET");
con.connect();
in = new BufferedInputStream(con.getInputStream());
out = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int n = 0;
while (-1 != (n = in.read(buf))) {
out.write(buf, 0, n);
}
return out.toByteArray();
} finally {
try {
out.close();
} catch (Exception e1) {
}
try {
in.close();
} catch (Exception e2) {
}
}
}
Self explanatory title, what is the int off from the android website, what does it do and why do i need it? I understand first and second argument from bytearrayoutputstream.write but not this one
from the android web:
OutputStream
Summary
void write(byte[] b, int off, int len)
Writes len bytes from the specified byte array starting at offset off to this output stream.
sample code:
public byte[] getUrlBytes(String urlSpec) throws IOException {
URL url = new URL(urlSpec);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
try {
ByteArrayOutputStream out = new ByteArrayOutputStream();
InputStream in = connection.getInputStream();
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
throw new IOException(connection.getResponseMessage() +
": with " +
urlSpec);
}
int bytesRead = 0;
byte[] buffer = new byte[1024];
while ((bytesRead = in.read(buffer)) > 0) {
out.write(buffer, 0, bytesRead);
}
out.close();
return out.toByteArray();
} finally {
connection.disconnect();
}
off is short for "offset", which means the index to start copying from. That, combined with len (or "length"), allows you to copy an arbitrary subsequence instead of the entire source array. For example:
byte[] array = {1,2,3,4};
ByteArrayOutputStream baos = new ByteArrayOutputStream();
baos.write(array, 1, 2); // copy 2 bytes from index 1
System.out.println(Arrays.toString(baos.toByteArray()));
// Output:
// [2, 3]
I would like to determine the number of bytes downloaded from the following working URL connection:
I have following code to implement:
.......
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream is = connection.getInputStream(); // throws an IOException
DataInputStream dis = new DataInputStream(new BufferedInputStream(is));
FileOutputStream fos = new FileOutputStream("C:\\Picture.jpeg");
int read =0;
byte[] bytes = new byte[1024];
while((read = dis.read(bytes)) != -1)
{
fos.write(bytes, 0, read);
}
System.out.println(read + " byte(s) copied");
The output from the last line is as follows:
Opening connection to http://www.xyz.com//Picture.jpeg...
Copying image resource (type: application/jpeg, modified on: 02/02/2010 4:19:21 AM)...
-1 byte(s) copied
What is the error of my code. please help me
int read =0;
int reddit = 0;
byte[] bytes = new byte[1024];
while((read = dis.read(bytes)) != -1)
{
fos.write(bytes, 0, read);
reddit += read;
}
//your read variable must have the value -1 at this point
System.out.println(reddit + " byte(s) copied");
int totalBytes = 0;
...
while((read = dis.read(bytes)) != -1)
{
totalBytes += read;
fos.write(bytes, 0, read);
}
I am trying to download/resume file. Resume seems to work, but whole download brings the problem. After executing this code testfile is 5242845. But it should be 5242880! I opened this two files in the hex editor and figured out that testfile missing some bytes at the end (begining is okay). This is the code:
String url = "http://download.thinkbroadband.com/5MB.zip";
String DESTINATION_PATH = "/sdcard/testfile";
URLConnection connection;
connection = (HttpURLConnection) url.openConnection();
File file = new File(DESTINATION_PATH);
if (file.exists()) {
downloaded = (int) file.length();
connection.setRequestProperty("Range", "bytes=" + (file.length()) + "-");
}
connection.setDoInput(true);
connection.setDoOutput(true);
BufferedInputStream in = new BufferedInputStream(connection.getInputStream());
FileOutputStream fos = (downloaded == 0) ? new FileOutputStream(DESTINATION_PATH) : new FileOutputStream(DESTINATION_PATH, true);
BufferedOutputStream bout = new BufferedOutputStream(fos, 1024);
byte[] data = new byte[1024];
int x = 0;
int i = 0;
int lenghtOfFile = connection.getContentLength();
while ((x = in.read(data, 0, 1024)) != -1) {
i++;
bout.write(data, 0, x);
downloaded += x;
}
I think that the problem is here while ((x = in.read(data, 0, 1024)) != -1) {.
For example we have file 1030 bytes long. First write is good, bout.write(data,0,1024); but next time while ((x = in.read(data, 0, 1024)) != -1) { gets -1, because 1030-1024=6 bytes left. And we are trying to write 1024 bytes! I know it should not be so, but it seems that it is how I said. How can I figure this? Thanks.
bout.flush();
and/or
bout.close();
You need to close your BufferedOutputStream to ensure that all that is buffered is sent to the buffered OutputStream.
google told me, there is a "available" method of bufferedinputstream, so you can write like
(I´m not an java guru)
while (in.available() > 0)
{
x = in.read(data, 0, 1024);
bout.write(data, 0, x);
}
URL url = new URL("http://download.thinkbroadband.com/20MB.zip");
URLConnection connection = url.openConnection();
File fileThatExists = new File(path);
OutputStream output = new FileOutputStream(path, true);
connection.setRequestProperty("Range", "bytes=" + fileThatExists.length() + "-");
connection.connect();
int lenghtOfFile = connection.getContentLength();
InputStream input = new BufferedInputStream(url.openStream());
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
output.write(data, 0 , count);
}
in this code I try to resume download. Target file is 20MB. But when I stop download on 10mb, then contunue, I get file with filesize 30MB. It seems that it continue writing to file, but cant partly download from server. Wget -c works great with this file. How can I resume file download?
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
if(ISSUE_DOWNLOAD_STATUS.intValue()==ECMConstant.ECM_DOWNLOADING){
File file=new File(DESTINATION_PATH);
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);
progressBar.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;
progressBar.setProgress(downloaded);
}
This is not my code, but it works.
I guess the problem you are facing is calling url.openStream() after url.openConnection().
url.openStream() is equivalent to url.openConnection().getInputStream(). Hence, you are requesting the url twice. Particularly the second time, it is not specifying the range property. Therefore download always starts at the beginning.
You should replace url.openStream() with connection.getInputStream().
This is what I am using to download the file in chunk Updating the UI with progress.
/*
* #param callback = To update the UI with appropriate action
* #param fileName = Name of the file by which downloaded file will be saved.
* #param downloadURL = File downloading URL
* #param filePath = Path where file will be saved
* #param object = Any object you want in return after download is completed to do certain operations like insert in DB or show toast
*/
public void startDownload(final IDownloadCallback callback, String fileName, String downloadURL, String filePath, Object object) {
callback.onPreExecute(); // Callback to tell that the downloading is going to start
int count = 0;
File outputFile = null; // Path where file will be downloaded
try {
File file = new File(filePath);
file.mkdirs();
long range = 0;
outputFile = new File(file, fileName);
/**
* Check whether the file exists or not
* If file doesn't exists then create the new file and range will be zero.
* But if file exists then get the length of file which will be the starting range,
* from where the file will be downloaded
*/
if (!outputFile.exists()) {
outputFile.createNewFile();
range = 0;
} else {
range = outputFile.length();
}
//Open the Connection
URL url = new URL(downloadURL);
URLConnection con = url.openConnection();
// Set the range parameter in header and give the range from where you want to start the downloading
con.setRequestProperty("Range", "bytes=" + range + "-");
/**
* The total length of file will be the total content length given by the server + range.
* Example: Suppose you have a file whose size is 1MB and you had already downloaded 500KB of it.
* Then you will pass in Header as "Range":"bytes=500000".
* Now the con.getContentLength() will be 500KB and range will be 500KB.
* So by adding the two you will get the total length of file which will be 1 MB
*/
final long lenghtOfFile = (int) con.getContentLength() + range;
FileOutputStream fileOutputStream = new FileOutputStream(outputFile, true);
InputStream inputStream = con.getInputStream();
byte[] buffer = new byte[1024];
long total = range;
/**
* Download the save the content into file
*/
while ((count = inputStream.read(buffer)) != -1) {
total += count;
int progress = (int) (total * 100 / lenghtOfFile);
EntityDownloadProgress entityDownloadProgress = new EntityDownloadProgress();
entityDownloadProgress.setProgress(progress);
entityDownloadProgress.setDownloadedSize(total);
entityDownloadProgress.setFileSize(lenghtOfFile);
callback.showProgress(entityDownloadProgress);
fileOutputStream.write(buffer, 0, count);
}
//Close the outputstream
fileOutputStream.close();
// Disconnect the Connection
if (con instanceof HttpsURLConnection) {
((HttpsURLConnection) con).disconnect();
} else if (con instanceof HttpURLConnection) {
((HttpURLConnection) con).disconnect();
}
inputStream.close();
/**
* If file size is equal then return callback as success with downlaoded filepath and the object
* else return failure
*/
if (lenghtOfFile == outputFile.length()) {
callback.onSuccess(outputFile.getAbsolutePath(), object);
} else {
callback.onFailure(object);
}
} catch (Exception e) {
e.printStackTrace();
callback.onFailure(object);
}
}
interface IDownloadCallback {
void onPreExecute(); // Callback to tell that the downloading is going to start
void onFailure(Object o); // Failed to download file
void onSuccess(String path, Object o); // Downloaded file successfully with downloaded path
void showProgress(EntityDownloadProgress entityDownloadProgress); // Show progress
}
public class EntityDownloadProgress {
int progress; // range from 1-100
long fileSize;// Total size of file to be downlaoded
long downloadedSize; // Size of the downlaoded file
public void setProgress(int progress) {this.progress = progress;}
public void setFileSize(long fileSize) {this.fileSize = fileSize;}
public void setDownloadedSize(long downloadedSize) {this.downloadedSize = downloadedSize;}
}
Check out this thread which has a problem similar to yours. If wget is working, then the server clearly supports resuming downloads. It looks like you're not setting the If-Range header as mentioned in the accepted answer of the above link. ie. add:
// Initial download.
String lastModified = connection.getHeaderField("Last-Modified");
// ...
// Resume download.
connection.setRequestProperty("If-Range", lastModified);
How about this?
public static void download(DownloadObject object) throws IOException{
String downloadUrl = object.getDownloadUrl();
String downloadPath = object.getDownloadPath();
long downloadedLength = 0;
File file = new File(downloadPath);
URL url = new URL(downloadUrl);
BufferedInputStream inputStream = null;
BufferedOutputStream outputStream = null;
URLConnection connection = url.openConnection();
if(file.exists()){
downloadedLength = file.length();
connection.setRequestProperty("Range", "bytes=" + downloadedLength + "-");
outputStream = new BufferedOutputStream(new FileOutputStream(file, true));
}else{
outputStream = new BufferedOutputStream(new FileOutputStream(file));
}
connection.connect();
inputStream = new BufferedInputStream(connection.getInputStream());
byte[] buffer = new byte[1024*8];
int byteCount;
while ((byteCount = inputStream.read(buffer)) != -1){
outputStream.write(buffer, 0, byteCount);
break;
}
inputStream.close();
outputStream.flush();
outputStream.close();
}
Used break; to test the code.. ;)
I have a way for your code to work.
First, check if the file exits or not
If the file exists, set the connection:
connection.setRequestProperty("Range", "bytes=" + bytedownloaded + "-");
If file does not exist, do the same download in a new file.
Since the question is tagged with Android:
Have you tried using DownloadManager.
It handles all this stuff nicely for you.