my application downloads a bitmap :
public byte[] getUrlImgContent(String urlstring) throws IOException
{
byte[] imageRaw = null;
URL url = new URL(urlstring);
HttpURLConnection urlConnection = (HttpURLConnection) url
.openConnection();
urlConnection.setUseCaches(false);
urlConnection.connect();
if (urlConnection.getResponseCode() == HttpURLConnection.HTTP_OK)
{
try
{
InputStream in = new BufferedInputStream(
urlConnection.getInputStream());
ByteArrayOutputStream out = new ByteArrayOutputStream();
int c;
while ((c = in.read()) != -1)
{
out.write(c);
}
out.flush();
imageRaw = out.toByteArray();
urlConnection.disconnect();
in.close();
out.close();
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return imageRaw;
}
return null;
}
and i'm directly converting it to bitmap and showing it in a zoomable-imageview
the problem : the application crashes if the file size is too big
what should I do to reduce the image's size ? (format : jpg)
Related
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();
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:
I am trying to download a video from a link, but it only downloads a small part of it, so it can't be watched at all. How would you download an entire video no matter how large the file is from a link?
try {
URL url;
byte[] buf;
int byteRead, byteWritten = 0;
url = new URL(fAddress);
outStream = new BufferedOutputStream(new FileOutputStream(destinationDir + "\\" + localFileName));
conn = url.openConnection();
is = conn.getInputStream();
buf = new byte[size];
while ((byteRead = is.read(buf)) != -1) {
outStream.write(buf, 0, byteRead);
byteWritten += byteRead;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
is.close();
outStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
It looks like server may redirect you to other location which your code doesn't handle. To get final location you can try method like (based on: http://www.mkyong.com/java/java-httpurlconnection-follow-redirect-example/):
public static String getFinalLocation(String address) throws IOException{
URL url = new URL(address);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
int status = conn.getResponseCode();
if (status != HttpURLConnection.HTTP_OK)
{
if (status == HttpURLConnection.HTTP_MOVED_TEMP
|| status == HttpURLConnection.HTTP_MOVED_PERM
|| status == HttpURLConnection.HTTP_SEE_OTHER)
{
String newLocation = conn.getHeaderField("Location");
return getFinalLocation(newLocation);
}
}
return address;
}
Now you simply need to change
url = new URL(fAddress);
to
url = new URL(getFinalLocation(fAddress));
I have a url of a file which works perfectly in browser and Java SE application but it gives me 403 forbidden error in servlet. Following are the codes of both Java SE program and the servlet
Java SE code
public class UrlDownload {
final static int size=1024;
public static void fileUrl(){
OutputStream outStream = null;
URLConnection uCon = null;
InputStream is = null;
try{
URL Url;
byte[] buf;
int ByteRead,ByteWritten=0;
Url= new URL("http://o-o---preferred---bharti-del2---v17--- lscache7.c.youtube.com/videoplayback?upn=6BFud0UQ_-0&sparams=cp%2Cgcr%2Cid%2Cip%2Cipbits%2Citag%2Cratebypass%2Csource%2Cupn%2Cexpire&fexp=900147%2C907217%2C922401%2C919804%2C920704%2C912806%2C906831%2C911406%2C913550%2C912706&key=yt1&itag=37&ipbits=8&signature=6EBF4572274A427AFF58E023CEC8B62439E0B914.BD6827306B81393BE3998FA0F0701E6F2701A3F8&mv=m&sver=3&mt=1345685891&ratebypass=yes&source=youtube&ms=au&gcr=in&expire=1345708167&ip=116.203.237.173&cp=U0hTSldLVl9LUUNOM19PRVpCOkV6WE5pcUF1NjQ5&id=9d8c9310d90eae67&quality=hd1080&fallback_host=tc.v17.cache7.c.youtube.com&type=video/mp4");
outStream = new BufferedOutputStream(new
FileOutputStream("video"));
uCon = Url.openConnection();
is = uCon.getInputStream();
buf = new byte[size];
while ((ByteRead = is.read(buf)) != -1)
{
System.out.println("Downloading file");
outStream.write(buf, 0, ByteRead);
ByteWritten += ByteRead;
}
System.out.println("Downloaded Successfully.");
}catch (Exception e) {
e.printStackTrace();
}finally {
try {
is.close();
outStream.close();
}catch (IOException e) {
e.printStackTrace();
}
}
}
}
Servlet Code
protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("video/mp4");
String url=request.getParameter("url");
URLConnection con = null;
BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
InputStream in=null;
byte[] buffer;
int ByteRead,ByteWritten=0;
try {
URL dUrl=new URL(url);
con=dUrl.openConnection();
in=con.getInputStream();
buffer = new byte[1024];
while ((ByteRead = in.read(buffer)) != -1)
{
System.out.println("Downloading file");
out.write(buffer, 0, ByteRead);
ByteWritten += ByteRead;
}
} finally {
out.close();
in.close();
}
}
url is the same url given as a parameter to this servlet
YouTube download URLs are intended for one-time use only -- they are bound to the IP range that they were initially generated for, and expire after some time. Hard-coding one in your application, as you've done here, will lead to inevitable failure.
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();
}
}
}