Convert office document to pdf and display it on the browser - jsf

Question

Please see the update question below (not the top one).
I tried to open any document type (especially PDF) on Liferay using this function. But I always get message Awt Desktop is not supported! as stated on the function. How can I enable the Awt Desktop? I tried searching over the internet and found nothing. Anyone help, pls? Thanks.
public void viewFileByAwt(String file) {
try {
File File = new File(getPath(file));
if (File.exists()) {
if (Desktop.isDesktopSupported()) {
Desktop.getDesktop().open(File);
} else {
System.out.println("Awt Desktop is not supported!");
}
} else {
//File is not exists
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
Source: http://www.mkyong.com/java/how-to-open-a-pdf-file-in-java/
UPDATE
As you see the code below, both mode (1 for download and 2 for preview) is working pretty well, but unfortunately the second mode (preview mode) is works only for PDF.
Now what I want to do is, while user clicking the preview button, files another than PDF (limited only for extension: DOC, DOCX, XLS, XLSX, ODT, ODS) must be converted to PDF first, and then display it on the browser with the same way as below code explained. Is it possible to do that? If it's too hard to have all of the converter on a function, then on a separated function each extension would be fine.
public StreamedContent getFileSelected(final StreamedContent doc, int mode) throws Exception {
//Mode: 1-download, 2-preview
try {
File localfile = new File(getPath(doc.getName()));
FileInputStream fis = new FileInputStream(localfile);
if (mode == 2 && !(doc.getName().substring(doc.getName().lastIndexOf(".") + 1)).matches("pdf")) {
localfile = DocumentConversionUtil.convert(doc.getName(), fis, doc.getName().substring(doc.getName().lastIndexOf(".") + 1), "pdf");
fis = new FileInputStream(localfile.getPath());
}
if (localfile.exists()) {
try {
PortletResponse portletResponse = (PortletResponse) FacesContext.getCurrentInstance().getExternalContext().getResponse();
HttpServletResponse res = PortalUtil.getHttpServletResponse(portletResponse);
if (mode == 1) res.setHeader("Content-Disposition", "attachment; filename=\"" + doc.getName() + "\"");
else if (mode == 2) res.setHeader("Content-Disposition", "inline; filename=\"" + doc.getName() + "\"");
res.setHeader("Content-Transfer-Encoding", "binary");
res.setContentType(getMimeType(localfile.getName().substring(localfile.getName().lastIndexOf(".") + 1)));
res.flushBuffer();
OutputStream out = res.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead;
while ((bytesRead = fis.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
buffer = new byte[4096];
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (fis != null)
fis.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}

Answer 1

Liferay is a portal server; its user interface runs in a browser. AWT is the Java 1.0 basis for desktop UIs.
I don't think AWT is the way to display it.
Why can't you open the file and stream the bytes to the portlet using the application/pdf MIME type?

Answer 2

You have to first install openoffice on your machine
http://www.liferay.com/documentation/liferay-portal/6.1/user-guide/-/ai/openoffice
After configuring openoffice with liferay, you can use DocumentConversionUtil class from liferay to convert documents.
DocumentConversionUtil.convert(String id, InputStream is, String sourceExtension,String targetExtension)
Above code will return inputstream. After this conversion you can show pdf in your browser
Hope this helps you!!