Develop Reference

Displaying Pdf Document by Servlet

I am trying to show pdf document in a iframe. I have set the source of the iframe to a servlet and passing some parameter to the servlet.
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
String docName = request.getParameter("docName");
String id = request.getParameter("id");
if (StringUtils.isNotBlank(id) && StringUtils.isNotBlank(docName)) {
DocumentService service = DamServiceProvider.PROVIDER.getDocumentService();
FileInBean fileInBean = new FileInBean();
fileInBean.setDocName(docName);
fileInBean.setId(Integer.valueOf(id));
FileDataBean fileDataBean = service.getFileDataBean(fileInBean);
if (fileDataBean.getStatusCode() == 0) {
Map<String, String> headerFieldMap = fileDataBean.getHeaderFieldMap();
String contentType = headerFieldMap.get("Content-type");
String contentLength = headerFieldMap.get("Content-Length");
String contentDisposition = headerFieldMap.get("Content-Disposition");
byte[] stream = fileDataBean.getStream();
ByteArrayInputStream inputStream = new ByteArrayInputStream(stream);
OutputStream outputStream = response.getOutputStream();
response.reset();
response.setBufferSize(4096);
response.setContentLength(Integer.valueOf(contentLength));
response.setContentType(contentType);
response.setHeader("Content-Disposition", contentDisposition);
System.out.println(contentDisposition);
IOUtils.copy(inputStream, outputStream);
outputStream.close();
inputStream.close();
}
}
} catch (Exception ex) {
Log.error(this, ex.getMessage());
}
}
Now in my page I have a master–detail interface. The master part contains a carousel of series of pdf file items. On clicking the item I am refreshing the detail view which contains the iframe.
I can see the servlet get called. Most of the times the iframe is displaying the pdf document. But sometimes it is showing weird xml structure which contains xml tags and some unreadable output. Please see the attach image:
This is not happening for a particular file. If a file shows this output, sometime later if click the item it shows the valid pdf and if an item shows a valid pdf sometime later it shows this kind of output if I click on it. When the iframe shows this type of output my browser displays an information that this pdf document might be corrupted.
I have checked the repository where the files are and I have found no issues there. All of them are valid pdf and I can download and open them by pdf reader.
I am unable to find the cause of this issue. Any pointer would be very helpful.
Update - 1
I have checked the output. It ends with %%EOF and has %PDF in the beginning.
Update - 2
I have checked in Chrome's Network Console the GET is returning mainly three types of content-type: application/pdf, text/plain, application/octet-stream.
application/pdf: it is showing the pdf.
text/plain it is showing the content that I mentioned above.
application/octet-stream didn't arise in Firefox but in Chrome and in that case it is opening the download file window.
I have placed a log in the servlet to see the content-type that returned from service. For all the cases it is application/pdf.

I think it maybe a problem with the content-Type, you can confirm if this is the espected in your browser with the developer tools (in the network console for Chrome).

try something like this.
File pdfFile = new File(this.pdfStoreLocation + pdfFileName);
response.setContentType("application/pdf");
response.setHeader("Content-Disposition", "attachment; filename=" + pdfFileName);
response.setContentLength((int) pdfFile.length());
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(pdfFile));
BufferedOutputStream bos = new BufferedOutputStream(response.getOutputStream());
// byte array declared
byte[] buf = new byte[2048];
boolean eof = false;
while (!eof) {
int length = bis.read(buf);
if (length == -1) {
eof = true;
}else {
bos.write(buf, 0, length);
}
}
try {
bis.close();
}catch (IOException ex) {
LOGGER.error("Exception in closing buffered input stream on pdf file->" + this.pdfStoreLocation + pdfFileName);
}
try {
bos.flush();
}catch (IOException ex) {
LOGGER.error("Exception in fliushing buffered output stream on pdf file->"
+ this.pdfStoreLocation + pdfFileName);
}
bos.close();

Display PDF in browser with a servlet

I want to display a PDF file in browser. I have the path to the pdf in JS and I am making a call to grab the PDF as a servlet from java. Here's what I have so far:
JavaScript:
RequestManager.getJSON(Config.server + "getPDF.json?pdfPath=" + this.pathToPdfFile, (function(data){
$("#" + this.divId).append('<object id="' + this.pdfObjectId + '" data="' + data + '" type="application/pdf" width="600" height="800"></object>');
ResizeManager.addResizeHandler(this.pdfObjectId, this.divId, -10, -10);
}).bind(this));
Java:
#RequestMapping("/getPDF")
public void pdfPathToServlet(Model model, HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
String pdfPath = request.getParameter("pdfPath");
if (pdfPath == null || pdfPath.equals(""))
throw new ServletException("Invalid or non-existent file parameter in UrlServlet servlet.");
if (pdfPath.indexOf(".pdf") == -1)
pdfPath += ".pdf";
File pdf = new File(pdfPath);
String pdfName = pdfPath.substring(pdfPath.lastIndexOf("/") + 1, pdfPath.length());
logger.debug(pdfName);
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try
{
stream = response.getOutputStream();
response.setContentType("application/pdf");
response.setHeader("Content-Disposition", "inline; filename='" + pdfName + "'");
FileInputStream input = new FileInputStream(pdf);
response.setContentLength((int) pdf.length());
buf = new BufferedInputStream(input);
int readBytes = 0;
while ((readBytes = buf.read()) != -1)
stream.write(readBytes);
}
catch (IOException ioe)
{
throw new ServletException(ioe.getMessage());
}
finally
{
if (stream != null)
stream.close();
if (buf != null)
buf.close();
}
}
My problem is that this is showing the binary output in my browser as text.
I'm not sure what I am doing incorrectly. I have tried changing the header to be attachment instead of inline, but that showed the same thing. I believe I want inline though, as I wish to show it in browser and not download it.

Your JavaScript part makes no sense. You're obtaining a PDF file as ajax response and then attempting to set it as data attribute of the <object> element. The data attribute must point to a real URL, not to the file content. Fix your JS accordingly:
$("#" + this.divId).append('<object id="' + this.pdfObjectId + '" data="' + Config.server + "getPDF.json?pdfPath=" + this.pathToPdfFile + '" type="application/pdf" width="600" height="800"></object>');
The webbrowser will take care about sending the appropriate HTTP request on the given URL and initializing/rendering the <object> element using the Adobe Acrobat Reader plugin — if any available, I'd rather enclose a PDF inside the <object> so that there's at least a graceful degradation to a download link.
Unrelated to the concrete question, that Java code is not part of a servlet at all, but a Spring MVC action. I recommend to get your terms straight and read in our Servlets wiki page to learn what they really are.

response.setHeader("Content-Disposition", "attachment;filename=" + pdfName);

response.setHeader("Content-Disposition", "inline; filename='" + pdfName + "'");
You cannot display a PDF inline. It needs to be alone on its own page (or Iframe).

JasperReport: how to download generated report?

I'm developing a web application on which user able to generate reports of some data. I'm using JasperReport do it. It's my first experience with JasperReport. So I've followed this tutorial.
Method described there can save reports on server, but I need that report would be downloadable after generation.
Could appreciate some help, thanks.

Your code should look something like this :
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
try {
String path = getServletContext().getRealPath("/reports/report1.jrxml");
jasReport = JasperCompileManager.compileReport(path);
System.out.println("Jasper Report : " + jasReport);
Connection con = MyConnFactory.getConnection();
System.out.println(con);
jasPrint = JasperFillManager.fillReport(jasReport,null,con);//, mapParam, con);
System.out.println("Jasper Print : " + jasPrint);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
// JasperExportManager.exportReportToPdfFile(jasPrint, "f:/nn.pdf");
// JasperExportManager.exportReportToPdfStream(jasPrint, baos);
// ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
// inputStream = bais;
ServletOutputStream sos=resp.getOutputStream();
JasperExportManager.exportReportToPdfStream(jasPrint, sos);
try {
MyConnFactory.getConnection().close();
sos.close();
} catch (SQLException ex) {
Logger.getLogger(MyReport.class.getName()).log(Level.SEVERE, null, ex);
}
} catch (JRException ex) {
Logger.getLogger(MyReport.class.getName()).log(Level.SEVERE, null, ex);
}
}

You will need to set these in your servlet code when trying to download the generated file. May need to change some parameters depending on the file format for your specific case.
response.setContentType("APPLICATION/OCTET-STREAM");
String disHeader = "Attachment;Filename=\"ReportFile.csv" + "\"";
response.setHeader("Content-Disposition", disHeader);

Either:
Save the file to a location accessible directly by the client, or
Stream the bytes back from a file (or other byte stream).
To do #1, you'll either have to save it "inside" the web app, which isn't possible when deploying a war, and tenuous if deploying an exploded war. Symlinks and container games can work around that.
To do #2, save it anywhere, and create a servlet that can take a request parameter that maps to the generated file (or whatever) and streams it back--searching for "download servlet" gives a ton of implementations.
Most frameworks offer similar functionality without writing a pure servlet.

How do I return a zip file to the browser via the response OutputStream?

In this situation, I have created a zip file containing search result files, and am trying to send it to the user. Here is the chunk of code I am currently trying to use.
File[] zippable = new File[files.size()];
File resultFile = ZipCreator.zip(files.toArray(zippable), results);
InputStream result = new FileInputStream(resultFile);
IOUtils.copy(result, response.getOutputStream());
However, this currently doesn't work quite right. Instead of returning the zip file that I have created, it returns an html file. If I manually change the file extension afterwards, I can see that the contents of the file are still the search results that I need. So the problem just lies in returning the proper extension to the response.
Does anyone have any advice for this situation?

You need to set the Content-Type response header to the value application/zip (or application/octet-stream, depending on the target browser). Additionally, you may want to send additional response headers indicating attachment status and filename.

You need to set the content type header to application/octet-stream prior to streaming the results. Depends on what implementation of response you are using on how you actually do this.

Here is some working code, just in case anyone needs it:
protected void doGet(HttpServletRequest request, HttpServletResponse response) {
// The zip file you want to download
File zipFile = new File(zipsResourcesPath + zipFileName);
response.setContentType("application/zip");
response.addHeader("Content-Disposition", "attachment; filename=" + zipFileName);
response.setContentLength((int) zipFile.length());
try {
FileInputStream fileInputStream = new FileInputStream(zipFile);
OutputStream responseOutputStream = response.getOutputStream();
int bytes;
while ((bytes = fileInputStream.read()) != -1) {
responseOutputStream.write(bytes);
}
} catch (IOException e) {
logger.error("Exception: " + e);
}
}
And the HTML:
<a class="btn" href="/path_to_servlet" target="_blank">Download zip</a>
Hope this helps!

So I found a hack for this : ) Just add ".zip" in your filename and set your content type as application/zip. Works like a charm.
response.setContentType("application/zip");
String licenseFileName = eId;
response.setHeader("Content-disposition", "attachment; filename=\"" + licenseFileName +".zip");

iText generated PDF not shown correctly in Chrome

I am using the iText library in Java to generate a pdf file. The idea is that a user fills in some information and that when the user clicks on the generate button the pdf is shown in a new tab in the browser. Now I have stumbled upon some problems doing this, which are :
- the URL does not change, so instead of /application/user.pdf I get /application/dashboard.xhtml
- I can save the pdf file in all browsers except for Chrome.
Please note that I don't want to save it on disc but simply show the pdf in the browser so the user can choose if he wants to save it.
Here is the code that I use to generate my pdf :
public static void createPdf(User user, byte languageNumber, HttpServletResponse response) {
Document document = new Document();
try {
/* PdfWriter writer = PdfWriter.getInstance(document,
new FileOutputStream("c://" + user.getUsername() + "_" + languageCode + ".pdf"));*/
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfWriter.getInstance(document, baos);
document.addTitle("Your CV");
document.addSubject("This is your CV");
document.addKeywords("CV");
document.addAuthor(user.getUsername());
document.open();
document.add(
new Paragraph(user.getPersonalInformation().getFirstname() + " " + user.getPersonalInformation().getLastname()));
document.close();
// setting some response headers
response.setHeader("Expires", "0");
response.setHeader("Cache-Control",
"must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
// setting the content type
response.setContentType("application/pdf");
response.setContentLength(baos.size());
//ServletOutputStream out = response.getOutputStream();
OutputStream out = response.getOutputStream();
baos.writeTo(out);
out.flush();
out.close();
} catch (DocumentException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
}
*This method is behind a button on my JSF page *
public String exportPdf() {
user = userService.retrieveLoginUser();
FacesContext context = FacesContext.getCurrentInstance();
try {
Object response = context.getExternalContext().getResponse();
if (response instanceof HttpServletResponse) {
HttpServletResponse hsr = (HttpServletResponse) response;
PdfCreator.createPdf(user, selectLanguage, hsr);
//Tell JSF to skip the remaining phases of the lifecycle
context.responseComplete();
}
return "../" + user.getUsername() + ".pdf";
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
Used technologies :
- JSF 2.0
- Facelets
- iText
Thanks in advance :D

The way that I have achieved this in the past is by creating a seperate Servlet to serve PDF documents directly. In the web.xml file you would specify the servlet mapping to *.pdf.
What you can do then is rather than override the FacesServlet response bytes to server the PDF file you just redirect the response to filename.pdf, passing needed parameters in the URL.
Your PDF servlet can actually do the work of building the necessary PDF, it will open in a seperate tab and the URL will match the response redirect.

Does chrome open the PDF and then not render it correctly? In that case, please open an issue at http://new.crbug.com and attach an example PDF file that shows the problem. Reply with the issue number here.