For a web application built on struts and jsp technologies, I'm looking for a good example which explains how to download files from the server side.
i manage to do it with this few lines of code :
just add this to your action :
OutputStream out = response.getOutputStream();
response.setContentType("application/rtf");
FileInputStream in = new FileInputStream("your_file_path");
byte[] buffer = new byte[4096];
int length;
while ((length = in.read(buffer)) > 0){
out.write(buffer, 0, length);
}
in.close();
out.flush();
Related
I need to merge multiple pdf files into one pdf and display it in my web browser.
I know how to display one file :
File file = new File(activite.getLienUploadUn());
FileInputStream inputStream = new FileInputStream(file);
byte[] buffer = new byte[8192];
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1)
{
baos.write(buffer, 0, bytesRead);
}
response.setHeader("Content-Disposition","inline; filename=\""+file.getName()+"\"");
response.setContentType("application/pdf");
ServletOutputStream outputStream = response.getOutputStream();
baos.writeTo(outputStream);
outputStream.flush();
I think I am going to use PdfBox and its PDFMergerUtility class to merge files :
PDFMergerUtility mergePdf = new PDFMergerUtility();
mergePdf.addSource(file);
mergePdf.mergeDocuments(MemoryUsageSetting.setupMainMemoryOnly());
But from there how can I convert the merged document into a byteArrayOutputStream?
You can call PDFMergerUtility.setDestinationStream(OutputStream destStream) to pass an output stream (javadoc).
I need to download some file which is more than 25 MB large, but my network only allow to request a file of 25 MB only.
I am using following code
const long DefaultSize = 26214400;
long Chunk = 26214400;
long offset = 0;
byte[] bytesInStream;
public void Download(string url, string filename)
{
long size = Size(url);
int blocksize = Convert.ToInt32(size / DefaultSize);
int remainder = Convert.ToInt32(size % DefaultSize);
if (remainder > 0) { blocksize++; }
FileStream fileStream = File.Create(#"D:\Download TEST\" + filename);
for (int i = 0; i < blocksize; i++)
{
if (i == blocksize - 1)
{
Chunk = remainder;
}
HttpWebRequest req = (HttpWebRequest)System.Net.WebRequest.Create(url);
req.Method = "GET";
req.AddRange(Convert.ToInt32(offset), Convert.ToInt32(Chunk+offset));
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
// StreamReader sr = new StreamReader(resp.GetResponseStream());
using (Stream responseStream = resp.GetResponseStream())
{
bytesInStream = new byte[Chunk];
responseStream.Read(bytesInStream, 0, (int)bytesInStream.Length);
// Use FileStream object to write to the specified file
fileStream.Seek((int)offset, SeekOrigin.Begin);
fileStream.Write(bytesInStream,0, bytesInStream.Length);
}
offset += Chunk;
}
fileStream.Close();
}
public long Size(string url)
{
System.Net.WebRequest req = System.Net.HttpWebRequest.Create(url);
req.Method = "HEAD";
System.Net.WebResponse resp = req.GetResponse();
resp.Close();
return resp.ContentLength;
}
It is properly writing content on disk but content is not working
You should check how much was read before write, something like this (and you don't need to remember the offset to seek, the seek is automatic when you write):
int read;
do
{
read = responseStream.Read(bytesInStream, 0, (int)bytesInStream.Length);
if (read > 0)
fileStream.Write(bytesInStream, 0, read);
}
while(read > 0);
There is a similar SO questions that might help you
Segmented C# file downloader
and
How to open multiple connections to download single file?
Also this code project article
http://www.codeproject.com/Tips/307548/Resume-Suppoert-Downloading
Range is zero based and you should subtract 1 from upper bound.
request.Headers.Range = new System.Net.Http.Headers.RangeHeaderValue(offset, chunkSize + offset - 1);
I published correct code fragment at the following link:
https://stackoverflow.com/a/48019611/1099716
Akka streams can help download file in small chunks from a System.IO.Stream using multithreading. https://getakka.net/articles/intro/what-is-akka.html
The Download method will append the bytes to the file starting with long fileStart. If the file does not exist, fileStart value must be 0.
using Akka.Actor;
using Akka.IO;
using Akka.Streams;
using Akka.Streams.Dsl;
using Akka.Streams.IO;
private static Sink<ByteString, Task<IOResult>> FileSink(string filename)
{
return Flow.Create<ByteString>()
.ToMaterialized(FileIO.ToFile(new FileInfo(filename), FileMode.Append), Keep.Right);
}
private async Task Download(string path, Uri uri, long fileStart)
{
using (var system = ActorSystem.Create("system"))
using (var materializer = system.Materializer())
{
HttpWebRequest request = WebRequest.Create(uri) as HttpWebRequest;
request.AddRange(fileStart);
using (WebResponse response = request.GetResponse())
{
Stream stream = response.GetResponseStream();
await StreamConverters.FromInputStream(() => stream, chunkSize: 1024)
.RunWith(FileSink(path), materializer);
}
}
}
I'm using following snippet for saving content:
private void writeToFile(NodeRef nodeRef, String content) throws IOException {
ContentWriter writer = contentService.getWriter(nodeRef, ContentModel.PROP_CONTENT, true);
InputStream contentStream = new ByteArrayInputStream(content.getBytes(encoding));
writer.setMimetype(mimeType);
writer.setEncoding(encoding);
writer.putContent(contentStream);
Map<QName, Serializable> repoProps = nodeService.getProperties(nodeRef);
ContentData contentData = (ContentData) repoProps.get(ContentModel.PROP_CONTENT);
if(contentData == null)
contentData = writer.getContentData();
contentData = ContentData.setEncoding(contentData, encoding);
contentData = ContentData.setMimetype(contentData, mimeType);
repoProps.put(ContentModel.PROP_CONTENT, contentData);
contentStream.close();
nodeService.setProperties(nodeRef, repoProps);
}
When I read content written this way within short period of time (depends on server load) in other place, old content is returned. So it looks like that maybe indexing is in progress, so before final commit old content is returned, is that possible? If so, is it possible to override this behavior and access newest possible content? Via contentUrl?
To avoid this behavior I'm using thread for each read request, which sleeps for some time at the beginning, but I really dislike this "solution".
Edit: I built from newest SVN source, running on Tomcat 6.0.35 on Linux (CentOS and Ubuntu); system load - i mean hundreds of files changing every few seconds.
Edit: reading looks like this:
private byte[] readFileContent(NodeRef nodeRef) throws IOException {
ContentReader reader = contentService.getReader(nodeRef, ContentModel.PROP_CONTENT);
if(reader == null)
return null;
InputStream originalInputStream = reader.getContentInputStream();
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
final int BUF_SIZE = 1 << 8; // 1KiB buffer
byte[] buffer = new byte[BUF_SIZE];
int bytesRead = -1;
while ((bytesRead = originalInputStream.read(buffer)) > -1) {
outputStream.write(buffer, 0, bytesRead);
}
originalInputStream.close();
return outputStream.toByteArray();
}
Ok, solved with simplier saving like this:
ContentWriter writer = contentService.getWriter(nodeRef, ContentModel.PROP_CONTENT, true);
InputStream contentStream = new ByteArrayInputStream(content.getBytes(encoding));
writer.setMimetype(mimeType);
writer.setEncoding(encoding);
writer.putContent(contentStream);
contentStream.close();
Previous saving was at place because of some content encoding problems, so testing shows if this works.
I have created a custom pipeline component which transforms a complex excel spreadsheet to XML. The transformation works fine and I can write out the data to check. However when I assign this data to the BodyPart.Data part of the inMsg or a new message I always get a routing failure. When I look at the message in the admin console it appears that the body contains binary data (I presume the original excel) rather than the XML I have assigned - see screen shot below. I have followed numerous tutorials and many different ways of doing this but always get the same result.
My current code is:
public Microsoft.BizTalk.Message.Interop.IBaseMessage Execute(Microsoft.BizTalk.Component.Interop.IPipelineContext pc, Microsoft.BizTalk.Message.Interop.IBaseMessage inmsg)
{
//make sure we have something
if (inmsg == null || inmsg.BodyPart == null || inmsg.BodyPart.Data == null)
{
throw new ArgumentNullException("inmsg");
}
IBaseMessagePart bodyPart = inmsg.BodyPart;
//create a temporary directory
const string tempDir = #"C:\test\excel";
if (!Directory.Exists(tempDir))
{
Directory.CreateDirectory(tempDir);
}
//get the input filename
string inputFileName = Convert.ToString(inmsg.Context.Read("ReceivedFileName", "http://schemas.microsoft.com/BizTalk/2003/file-properties"));
swTemp.WriteLine("inputFileName: " + inputFileName);
//set path to write excel file
string excelPath = tempDir + #"\" + Path.GetFileName(inputFileName);
swTemp.WriteLine("excelPath: " + excelPath);
//write the excel file to a temporary folder
bodyPart = inmsg.BodyPart;
Stream inboundStream = bodyPart.GetOriginalDataStream();
Stream outFile = File.Create(excelPath);
inboundStream.CopyTo(outFile);
outFile.Close();
//process excel file to return XML
var spreadsheet = new SpreadSheet();
string strXmlOut = spreadsheet.ProcessWorkbook(excelPath);
//now build an XML doc to hold this data
XmlDocument xDoc = new XmlDocument();
xDoc.LoadXml(strXmlOut);
XmlDocument finalMsg = new XmlDocument();
XmlElement xEle;
xEle = finalMsg.CreateElement("ns0", "BizTalk_Test_Amey_Pipeline.textXML",
"http://tempuri.org/INT018_Workbook.xsd");
finalMsg.AppendChild(xEle);
finalMsg.FirstChild.InnerXml = xDoc.FirstChild.InnerXml;
//write xml to memory stream
swTemp.WriteLine("Write xml to memory stream");
MemoryStream streamXmlOut = new MemoryStream();
finalMsg.Save(streamXmlOut);
streamXmlOut.Position = 0;
inmsg.BodyPart.Data = streamXmlOut;
pc.ResourceTracker.AddResource(streamXmlOut);
return inmsg;
}
Here is a sample of writing the message back:
IBaseMessage Microsoft.BizTalk.Component.Interop.IComponent.Execute(IPipelineContext pContext, IBaseMessage pInMsg)
{
IBaseMessagePart bodyPart = pInMsg.BodyPart;
if (bodyPart != null)
{
using (Stream originalStrm = bodyPart.GetOriginalDataStream())
{
byte[] changedMessage = ConvertToBytes(ret);
using (Stream strm = new AsciiStream(originalStrm, changedMessage, resManager))
{
// Setup the custom stream to put it back in the message.
bodyPart.Data = strm;
pContext.ResourceTracker.AddResource(strm);
}
}
}
return pInMsg;
}
The AsciiStream used a method like this to read the stream:
override public int Read(byte[] buffer, int offset, int count)
{
int ret = 0;
int bytesRead = 0;
byte[] FixedData = this.changedBytes;
if (FixedData != null)
{
bytesRead = count > (FixedData.Length - overallOffset) ? FixedData.Length - overallOffset : count;
Array.Copy(FixedData, overallOffset, buffer, offset, bytesRead);
if (FixedData.Length == (bytesRead + overallOffset))
this.changedBytes = null;
// Increment the overall offset.
overallOffset += bytesRead;
offset += bytesRead;
count -= bytesRead;
ret += bytesRead;
}
return ret;
}
I would first of all add more logging to your component around the MemoryStream logic - maybe write the file out to the file system so you can make sure the Xml version is correct. You can also attach to the BizTalk process and step through the code for the component which makes debugging a lot easier.
I would try switching the use of MemoryStream to a more basic custom stream that writes the bytes for you. In the BizTalk SDK samples for pipeline components there are some examples for a custom stream. You would have to customize the stream sample so it just writes the stream. I can work on posting an example. So do the additional diagnostics above first.
Thanks,
This is my code and I can't seem to get the file I have in my FileUploadCotrol into the FILESTREAM.
// The buffer size is set to 2kb
int buffLength = 2048;
byte[] buff = new byte[buffLength];
int contentLen;
// Opens a file stream (System.IO.FileStream) to read the file to be uploaded
FileStream fs = fileInf.OpenRead();
try
{
// Stream to which the file to be upload is written
Stream strm = reqFTP.GetRequestStream();
// Read from the file stream 2kb at a time
contentLen = fs.Read(buff, 0, buffLength);
// Till Stream content ends
while (contentLen != 0)
{
// Write Content from the file stream to the FTP Upload Stream
strm.Write(buff, 0, contentLen);
contentLen = fs.Read(buff, 0, buffLength);
}
// Close the file stream and the Request Stream
strm.Close();
fs.Close();
}
It seems the I should be using the Fileupload control to do the from my website, yet it seams strange that the control creates a stream and not a filestream. Yes I am FTPing a file.
Here is a sample method that takes the two types we are targeting, FileInfo and FtpWebRequest, as arguments and streams data between them. I believe this will work.
void UploadFileToFtp(FileInfo file, FtpWebRequest req)
{
int buffLength = 2048;
using (var reader = new BinaryReader(file.OpenRead()))
{
using (var writer = new BinaryWriter(req.GetRequestStream()))
{
while (reader.PeekChar() > 0) writer.Write(reader.ReadBytes(buffLength));
}
}
}
Hope this helps!