I am encountering with a senerior like this:
My project has a servlet to catch a request from perl. The request is to download a file. The request is a multipartRequest.
@RequestMapping(value = "/*", method = RequestMethod.POST)
public void tdRequest(@RequestHeader("Authorization") String authenticate,
HttpServletResponse response,
HttpServletRequest request) throws Exception
{
if (ServletFileUpload.isMultipartContent(request))
{
ServletFileUpload sfu = new ServletFileUpload();
FileItemIterator items = sfu.getItemIterator(request);
while (items.hasNext())
{
FileItemStream item = items.next();
if (("action").equals(item.getFieldName()))
{
InputStream stream = item.openStream();
String value = Streams.asString(stream);

if (("upload").equals(value))
{
uploadRequest(items, response);
return;
}
else if (("download").equals(value))
{
downloadRequest(items, response);
return;
}
The problem is not here, it appears on the downloadRequest() function.
void downloadRequest(FileItemIterator items,
HttpServletResponse response) throws Exception
{
log.info("Start downloadRequest.......");
OutputStream os = response.getOutputStream();
File file = new File("D:\\clip.mp4");
FileInputStream fileIn = new FileInputStream(file);
//while ((datablock = dataOutputStreamServiceImpl.readBlock()) != null)
byte[] outputByte = new byte[ONE_MEGABYE];
while (fileIn.read(outputByte) != -1)
{

System.out.println("--------" + (i = i + 1) + "--------");
System.out.println(new Date());
//dataContent = datablock.getContent();
System.out.println("Start write " + new Date());
os.write(outputByte, 0,outputByte.length);
System.out.println("End write " + new Date());
//System.out.println("----------------------");
}
os.close();
}
}
I try to read and write blocks of 1MB from the file. However, it takes too long for downloading the whole file. ( my case is 20mins for file of 100MB)
I try to sysout and I saw a result like this:
The first few blocks can read, write data realy fast:
--------1--------
Mon Dec 07 16:24:20 ICT 2015
Start write Mon Dec 07 16:24:20 ICT 2015
End write Mon Dec 07 16:24:21 ICT 2015
--------2--------
Mon Dec 07 16:24:21 ICT 2015
Start write Mon Dec 07 16:24:21 ICT 2015
End write Mon Dec 07 16:24:21 ICT 2015
--------3--------
Mon Dec 07 16:24:21 ICT 2015
Start write Mon Dec 07 16:24:21 ICT 2015
End write Mon Dec 07 16:24:21 ICT 2015
But the next block is slower than the previous
--------72--------
Mon Dec 07 16:29:22 ICT 2015
Start write Mon Dec 07 16:29:22 ICT 2015
End write Mon Dec 07 16:29:29 ICT 2015
--------73--------
Mon Dec 07 16:29:29 ICT 2015
Start write Mon Dec 07 16:29:29 ICT 2015
End write Mon Dec 07 16:29:37 ICT 2015

--------124--------
Mon Dec 07 16:38:22 ICT 2015
Start write Mon Dec 07 16:38:22 ICT 2015
End write Mon Dec 07 16:38:35 ICT 2015
--------125--------
Mon Dec 07 16:38:35 ICT 2015
Start write Mon Dec 07 16:38:35 ICT 2015
End write Mon Dec 07 16:38:48 ICT 2015
The problem is in the os.write() I realy cannot understand how the outputStream write, why it take such a long time like that? or I made some mistakes?
Sorry for my bad english. I realy need your support. Thank in advance!
This is the perl code from the client side
# ----- get connected to download the file
#
$Response = $ua->request(POST $remoteHost ,
Content_Type => 'form-data',
Authorization => $Authorization,
'Proxy-Authorization' => $Proxy_Authorization ,

Content => [ DOS => 1 ,
action => 'download' ,
first_run => 0 ,
dl_filename => $dl_filename ,
delivery_dir => $delivery_dir ,
verbose => $Verbose ,
debug => $debug ,
version => $VERSION
]
);

unless ($Response->is_success) {
my $Msg = $Response->error_as_HTML;

# Remove HTML tags - we're in a DOS shell!
$Msg =~ s/]+>//g;

print "ERROR! SERVER RESPONSE:\n$Msg\n";
print "$remoteHost\n\n" if $Options{'v'};
Error "Could not connect to " . $remoteHost ;
}

my $Result2 = $Response->content();

Error "Abnormal termination...\n$Result2" if $Result2 =~ /_APP_ERROR_/;

open(F, ">$dl_filename") or Error "Could not open '$dl_filename'!";
binmode F; # unless $dl_filename =~ /\.txt$|\.htm$/;
print F $Result2;
close F;
print "received.\n";

}


Check Solution