I have written a java controller which handles any download request from the server. My files are present in the server however I am getting 0 kB file downloaded every time. The file is getting downloaded but the size is always 0 Kb. Please help me. Here is my code -
#RequestMapping(value="/downloadFile/{docId}")
public void getDownloadFile(#PathVariable(value = "docId") Integer docId, HttpServletResponse response) throws Exception {
String userName = getUserName();
try {
DocVault documentsVault = documentsVaultRepository.findDocumentAttachment(docId);
String fileName = documentsVault.getDocumentName();
int customerId = documentsVault.getCustomerId();
Map<Integer, String> customerInfo = cspUtils.getCustomersInfo(userName);
Set<Integer> customerIds = customerInfo.keySet();
for (int custId : customerIds) {
if (custId == customerId) {
String path = env.getProperty("doc.rootfolder") + File.separator + documentsVault.getFileName();
service.downloadFile(fileName, path, response);
} else {
logger.info("Customer not linked to user");
}
}
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
Implementation -
public void downloadFile(String fileName, String path, HttpServletResponse response) {
try {
File downloadFile = new File(path);
FileInputStream inputStream = new FileInputStream(downloadFile);
response.setContentLength((int) downloadFile.length());
response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
// get output stream of the response
OutputStream outStream = response.getOutputStream();
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = -1;
// write bytes read from the input stream into the output stream
while ((bytesRead = inputStream.read(buffer)) != -1) {
outStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
I am not getting any exceptions. Please help.
Thank you in advance.
response.setContentLength((int) downloadFile.length());
Remove this. The container will set it automatically.
int bytesRead = -1;
You don't need to initialize this variable. It gets assigned in the very next line.
Thank you for your help. What I figured out was there was a problem with my Content Disposition header. I was passing only the file name without extension. When I passed the full file name then it worked perfectly. Size and Extension of the file were proper.
Related
I am trying to allow a user to download a file (attachment) using Java to serve up the download. I have been partially successful. The file is read, and on the client side there is a prompt for a download. A file is saved successfully, but it has 0 bytes. Here is my server side code:
String stored = "/var/lib/tomcat/webapps/myapp/attachments/" + request.getParameter("stored");
String realname = request.getParameter("realname");
// Open the input and output streams
FileInputStream attachmentFis = new FileInputStream(stored);
FileOutputStream attachmentFos = new FileOutputStream(realname);
try {
// Send the file
byte[] attachmentBuffer = new byte[1024];
int count = 0;
while((count = attachmentFis.read(attachmentBuffer)) != -1) {
attachmentFos.write(attachmentBuffer, 0, count);
}
} catch (IOException e) {
// Exception handling
} finally {
// Close the streams
attachmentFos.flush();
attachmentFos.close();
attachmentFis.close();
}
For context, this is in a servlet. The files have an obfuscated name, which is passed as "stored" here. The actual file name, the name the user will see, is "realname".
What do I need to do to get the actual file to arrive at the client end?
EDIT
Following suggestions in the comments, I changed the write to include the 0, count parameters and put the close stuff in a finally block. However, I am still getting a 0 byte file when I attempt a download.
EDIT 2
Thanks to the logging suggestion from Dave the Dane, I discovered the file was being written locally. A bit of digging and I found I needed to use response.getOutputStream().write instead of a regular FileOutputStream. I have been successful in getting a file to download through this method. Thank you all for your helpful suggestions.
As others have observed, you'd be better off using try-with-resources & let that handle the closing.
Assuming you have some Logging Framework available, maybe the following would cast light on the matter...
try {
LOG.info ("Requesting....");
final String stored = "/var/lib/tomcat/webapps/myapp/attachments/" + request.getParameter("stored");
LOG.info ("stored.......: {}", stored);
final String realname = request.getParameter("realname");
LOG.info ("realname.....: {}", realname);
final File fileStored = new File(stored);
LOG.info ("fileStored...: {}", fileStored .getCanonicalPath());
final File fileRealname = new File(realname);
LOG.info ("fileRealname.: {}", fileRealname.getCanonicalPath());
try(final InputStream attachmentFis = new FileInputStream (fileStored);
final OutputStream attachmentFos = new FileOutputStream(fileRealname))
{
final byte[] attachmentBuffer = new byte[64 * 1024];
int count;
while((count = attachmentFis.read (attachmentBuffer)) != -1) {
; attachmentFos.write(attachmentBuffer, 0, count);
LOG.info ("Written......: {} bytes to {}", count, realname);
}
attachmentFos.flush(); // Probably done automatically in .close()
}
LOG.info ("Done.");
}
catch (final Exception e) {
LOG.error("Problem!.....: {}", request, e);
}
If it won't reach the finally block, you should stop ignoring the IOException which is being thrown:
catch (IOException e) {
// Exception handling
System.err.println(e.getMessage());
}
I'd asssume that the realname is just missing an absolute path.
I am trying to call this method from my filter and i am successfully able to download the excel but after the download when i open the excel it shows that it is corrupted but when i see the file on server files opens fine without any error.
Excel error : excel cannot open the file "filename" because the file format or file extension is not valid.
public static void downloadFileFromServer(HttpServletResponse response, String sourceFile,
Boolean isFilenameHavingTimestamp,Boolean deleteTempFile) throws IOException, Exception {
logger.debug("Inside ServiceUtils.downloadFileFromServer()");
// splitting serverPath and fileName
String serverHomeDirectory[] = sourceFile.split("\\\\|/");
String fileName = serverHomeDirectory[serverHomeDirectory.length - 1];
fileName = URLDecoder.decode(fileName, "UTF-8");
if (Boolean.TRUE.equals(isFilenameHavingTimestamp)) {
fileName = removeTimestampFromFilename(fileName);
}
response.setContentType("application/octet-stream");
response.addHeader("content-disposition", "attachment; filename=\"" + fileName + "\"");
try (ServletOutputStream out = response.getOutputStream();
FileInputStream in = new FileInputStream(sourceFile);) {
int octet = 0;
while ((octet = in.read()) != -1) {
out.write(octet);
}
} catch (Exception e) {
logger.error("Exception in ServiceUtils.downloadFileFromServer(): ", e);
throw new Exception(ExceptionMessage.ERROR_DOWNLOAD_EXCEL_FILE);
} finally {
// check if file needs to be deleted after download
/*if(deleteTempFile)
deleteTempFile(sourceFile);*/
}
}
Problem was that the response already had a string and code was writing the file appending the existing response in the buffer.
Solved the problem by adding below code before setContentType()
response.reset();
I have to download an image from the nasa website. Problem is, that my code sometimes works, sucessfully downloading an image, while sometimes saves only 186B (don't know why exactly 186).
Problems is for sure connected with the way nasa sahres those photos. For instance, an image from that link https://mars.jpl.nasa.gov/msl-raw-images/msss/00001/mcam/0001ML0000001000I1_DXXX.jpg is saved sucessfully, while from that link https://mars.nasa.gov/mer/gallery/all/2/f/001/2F126468064EDN0000P1001L0M1-BR.JPG fails.
Here is my code
public static void saveImage(String imageUrl, String destinationFile){
URL url;
try {
url = new URL(imageUrl);
System.out.println(url);
InputStream is = url.openStream();
OutputStream os = new FileOutputStream(destinationFile);
byte[] b = new byte[2048];
int length;
while ((length = is.read(b)) != -1) {
os.write(b, 0, length);
}
is.close();
os.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Does someone have an idea, why is doesn't work?
public boolean downloadPhotosSol(int i) throws JSONException, IOException {
String url0 = "https://api.nasa.gov/mars-photos/api/v1/rovers/spirit/photos?sol=" + this.chosenMarsDate + "&camera=" + this.chosenCamera + "&page=" + i + "&api_key=###";
JSONObject json = JsonReader.readJsonFromUrl(url0);
if(json.getJSONArray("photos").length() == 0) return true;
String workspace = new File(".").getCanonicalPath();
String pathToFolder = workspace+File.separator+this.getManifest().getName() + this.chosenMarsDate + this.chosenCamera +"Strona"+i;
new File(pathToFolder).mkdirs();
for(int j = 0;j<json.getJSONArray("photos").length();j++) {
String url = ((JSONObject) json.getJSONArray("photos").get(j)).getString("img_src");
SaveImage.saveImage(url, pathToFolder+File.separator+"img"+j+".jpg");
}
return false;
}
When you get a 186 byte file, open it with a text editor and see what is inside. It could contain an HTTP error message in HTML format. If instead you see the first 186 bytes of your image file, then something is not working right with your program.
EDIT: From your comments it looks like you are getting an HTTP 301 response, which is a redirect to another location. A web browser handles this automatically without you noticing. However, your Java program is not following the redirect to the new location. You need to use an HTTP Java library that handles redirects.
Best and short way of doing it:
try(InputStream in = new URL("http://example.com/image.jpg").openStream()){
Files.copy(in, Paths.get("C:/File/To/Save/To/image.jpg"));
}
I used Java to copy file but it appeared a exception (the system can not find the file specified).
The codes are
public static void copyFile(String sourceFile, String destFile){
try {
InputStream in = new FileInputStream(sourceFile);
OutputStream os = new FileOutputStream(destFile);
byte[] buffer = new byte[1024];
int count;
while ((count = in.read(buffer)) > 0) {
os.write(buffer, 0, count);
}
in.close();
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
The test codes
public static void main(String[] args) {
String name = getFileName("D:/z/temp.txt");
String target = "D:/tem.txt";
copyFile(name, target);
}
the exception is java.io.FileNotFoundException: temp.txt(the system can not find the file specified)
The file 'temp.txt' is existence.
The path is right no problem.
I guess that is the problem of Permissions. who can come up with the answer thanks!
We need to see the method getFileName() to be sure, but based on the error message and the method name, I suspect the problem is just that this method returns only the name of the file, removing the path info, so that the file is, indeed, not found.
I've got some Java code using a servlet and Apache Commons FileUpload to upload a file to a set directory. It's working fine for character data (e.g. text files) but image files are coming out garbled. I can open them but the image doesn't look like it should. Here's my code:
Servlet
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
String customerPath = "\\leetest\\";
// Check that we have a file upload request
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
if (isMultipart) {
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload();
// Parse the request
FileItemIterator iter = upload.getItemIterator(request);
while (iter.hasNext()) {
FileItemStream item = iter.next();
String name = item.getFieldName();
if (item.isFormField()) {
// Form field. Ignore for now
} else {
BufferedInputStream stream = new BufferedInputStream(item
.openStream());
if (stream == null) {
LOGGER
.error("Something went wrong with fetching the stream for field "
+ name);
}
byte[] bytes = StreamUtils.getBytes(stream);
FileManager.createFile(customerPath, item.getName(), bytes);
stream.close();
}
}
}
} catch (Exception e) {
throw new UploadException("An error occured during upload: "
+ e.getMessage());
}
}
StreamUtils.getBytes(stream) looks like:
public static byte[] getBytes(InputStream src, int buffsize)
throws IOException {
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
byte[] buff = new byte[buffsize];
while (true) {
int nBytesRead = src.read(buff);
if (nBytesRead < 0) {
break;
}
byteStream.write(buff);
}
byte[] result = byteStream.toByteArray();
byteStream.close();
return result;
}
And finally FileManager.createFile looks like:
public static void createFile(String customerPath, String filename,
byte[] fileData) throws IOException {
customerPath = getFullPath(customerPath + filename);
File newFile = new File(customerPath);
if (!newFile.getParentFile().exists()) {
newFile.getParentFile().mkdirs();
}
FileOutputStream outputStream = new FileOutputStream(newFile);
outputStream.write(fileData);
outputStream.close();
}
Can anyone spot what I'm doing wrong?
Cheers,
Lee
One thing I don't like is here in this block from StreamUtils.getBytes():
1 while (true) {
2 int nBytesRead = src.read(buff);
3 if (nBytesRead < 0) {
4 break;
5 }
6 byteStream.write(buff);
7 }
At line 6, it writes the entire buffer, no matter how many bytes are read in. I am not convinced this will always be the case. It would be more correct like this:
1 while (true) {
2 int nBytesRead = src.read(buff);
3 if (nBytesRead < 0) {
4 break;
5 } else {
6 byteStream.write(buff, 0, nBytesRead);
7 }
8 }
Note the 'else' on line 5, along with the two additional parameters (array index start position and length to copy) on line 6.
I could imagine that for larger files, like images, the buffer returns before it is filled (maybe it is waiting for more). That means you'd be unintentionally writing old data that was remaining in the tail end of the buffer. This is almost certainly happening most of the time at EoF, assuming a buffer > 1 byte, but extra data at EoF is probably not the cause of your corruption...it is just not desirable.
I'd just use commons io Then you could just do an IOUtils.copy(InputStream, OutputStream);
It's got lots of other useful utility methods.
Are you sure that the image isn't coming through garbled or that you aren't dropping some packets on the way in.
I don't know what difference it makes, but there seems to be a mismatch of method signatures. The getBytes() method called in your doPost() method has only one argument:
byte[] bytes = StreamUtils.getBytes(stream);
while the method source you included has two arguments:
public static byte[] getBytes(InputStream src, int buffsize)
Hope that helps.
Can you perform a checksum on your original file, and the uploaded file and see if there is any immediate differences?
If there are then you can look at performing a diff, to determine the exact part(s) of the file that are missing changed.
Things that pop to mind is beginning or end of stream, or endianness.