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JSF command button can be clicked only once when calling servlet for file download

I have some command buttons in a jsf, one of which when clicked when create a file and download. In the action class that handle the jsf action , I create the url object that has the URL for calling the Servlet.
This all works , the file is downloaded one time when I click on the button , but the issue is , I cannot click on the button or any other command buttons on the page after this. Why is the request not complete? Please help.
<h:commandButton id="filedownloadbtn" action="#{fileDownloadInit.submit}" value = "thisform">
Action
try {
String baseURL = facesContext.getCurrentInstance().getExternalContext().getRequestContextPath();
String url = baseURL + "/DataloadServlet";
facesContext.getCurrentInstance().getExternalContext().redirect(url);
return null;
} finally {
facesContext.responseComplete();
}'
DataloadServlet
public Object[] getFileNameAndData(HttpServletRequest request)
{
ByteArrayOutputStream stream = new ByteArrayOutputStream();
//does some processing...
return new Object[] {fileName, stream.toByteArray()};
}
FileDownloadservlet
public abstract class FileDownloadservlet extends javax.servlet.http.HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
Object[] file = getFileNameAndData(request);
if (file != null)
{
String fileName = (String)file[0];
byte[] fileData = (byte[])file[1];
response.setHeader("Content-Disposition", "attachment;filename=\"" + fileName +"\"");
response.setHeader("Cache-Control", "no-cache, no-store"); // HTTP 1.1.
response.setHeader("Pragma", "no-cache"); // HTTP 1.0.
String contentType = "application/vnd.ms-excel";
response.setContentType(");
response.setContentLength(fileData.length);
try
{
OutputStream output = response.getOutputStream();
output.write(fileData);
output.flush();
output.close();
}
catch (IOException ex)
{
}
}
}

Unable to download file in Spring MVC

My Controller to which the request is mapped-
I return the value from AJAX, to the controller-
$.ajax({
type: 'GET',
dataType: 'json',
contentType:"application/json",
url:"/Putty/downloadProcess/?param="+param
});
#RequestMapping(value = "/downloadProcess", method = RequestMethod.GET)
protected void download(#RequestParam("param") String value, HttpServletResponse response)
throws ServletException, IOException {
Properties prop = new Properties();
InputStream input = new FileInputStream("config.properties");;
prop.load(input);
System.out.println(value);
String path = prop.getProperty("path.MS1");
String filepath= path.concat(value);
System.out.println(filepath);
File downloadFile = new File(filepath);
FileInputStream inStream = new FileInputStream(downloadFile);
String mimeType = "application/octet-stream";
System.out.println("MIME type: " + mimeType);
// modifies response
response.setContentType(mimeType);
response.setContentLength((int) downloadFile.length());
// forces download
String headerKey = "Content-Disposition";
String headerValue = String.format("attachment; filename=\"%s\"", downloadFile);
response.setHeader(headerKey, headerValue);
System.out.println(response);
// obtains response's output stream
OutputStream outStream = response.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, bytesRead);
}
inStream.close();
outStream.close();
This displays the filenames on my JSP
<c:forEach var="listValue" items="${files}">
<label onClick="download('${listValue}')">${listValue}</label>
<br>
</c:forEach>
The problem is that, I can see the MIME type on my console, along with the value returned by AJAX- The filename. But I do not get the Download dialog box, when I click on the file names, displayed on my JSP. Am I not handling the requests properly or I am missing something else.
Thanks!

Try it
ServletOutputStream out = response.getOutputStream();
response.setContentType("application/octet-stream");
if (file.isFile())
{
response.setHeader("Content-Disposition", "attachment;filename=\"" + downloadFile.getName() + "\"");
try (FileInputStream inputStream = new FileInputStream(downloadFile ))
{
IOUtils.copy(inputStream, out);
}
}

The Open/Save dialogue appears by default so we can not force anything. It is a browser specific settings that you cant change on the client side.
For Mozilla Firefox example :

How can I reuse JAX-RS Response into HttpServletResponse?

I have a Servlet which makes a request to my Rest API, and I want it to return the API Response content to the final user through the HttpServletResponse.
The content is actually a .xls file to download which I put in the Response with the StreamingOutput Object.
How can I do that ? I can't cast the Response into a HttpServletResponse
Rest API method :
#GET
#Produces( MediaType.APPLICATION_JSON )
#Path("bla")
public Response getTopicByName() {
final Workbook wb = new HSSFWorkbook();
StreamingOutput stream = new StreamingOutput() {
#Override
public void write(OutputStream output) throws IOException, WebApplicationException {
wb.write(output);
}
};
responseBuilder = responseBuilder.entity(stream);
responseBuilder = responseBuilder.status(Response.Status.OK);
responseBuilder = responseBuilder.header("Content-Disposition", "attachment; filename=" + device + ".xls");
return responseBuilder.build();
}
Servlet POST method :
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Client client = ClientBuilder.newClient();
WebTarget target = client.target(url);
Response res = target. request().get();
if (res.getStatus() == 200) {
// how to put res stream into response stream ?
ServletOutputStream stream = response.getOutputStream();
}
client.close();
}
EDIT :
I tried TedTrippin method and after finding out the way to recover an InputStream from the Response, it worked well.
But I keep getting corrupted xls files. And it is quite annoying. I don't get those corrupted files when I make the request directly from the browser.
Got any clues where it comes from ?
POST method :
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Client client = ClientBuilder.newClient();
WebTarget target = client.target(url + param + format);
Response res = target.request().get();
if (res.getStatus() == 200) {
response.setHeader("Content-Disposition", "attachment; filename=test.xls");
InputStream in = res.readEntity(InputStream.class);
ServletOutputStream out = response.getOutputStream();
byte[] buffer = new byte[1024];
while (in.read(buffer) >= 0) {
out.write(buffer);
}
out.flush();
}
client.close();
}

Simplest way is to read the response stream and write it straight to the response output stream. Either use a library function from IOUtils or Guava or pure java...
try (InputStream in = ...;
OutputStream out = ...) {
byte[] buffer = new byte[1024];
while (in.read(buffer) >= 0)
out.write(buffer);
} catch (IOException ex) {
...
}
A nicer (depending on your view) way would be to read/save the response as a temporary file then you could return that or write it to the output stream.
Third approach would be to create a pipe, but I don't think that would be applicable here.

Download pdf directly to browser when generated with itext

I am using itext to generate a pdf file from an html string. I get this error in my console:
Uncaught Error: Syntax error, unrecognized expression: %PDF-1.4
This is the code in my controller.
#RequestMapping(value = "/print",method = RequestMethod.POST)
public void print(String html,HttpServletResponse response,HttpServletRequest request) throws IOException,DocumentException {
try{
Document document = new Document();
// step 2
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfWriter.getInstance(document, baos);
// step 3
document.open();
document.add(new Paragraph(html));
// step 5
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");
// the contentlength
response.setContentLength(baos.size());
// write ByteArrayOutputStream to the ServletOutputStream
OutputStream os = response.getOutputStream();
baos.writeTo(os);
os.flush();
}
catch(DocumentException e) {
throw new IOException(e.getMessage());
}

what you need to do is to stream the PDF file's bytes directly to the output stream and flush the response. In Spring you can do this like this:
#RequestMapping(value="/displayProcessFile/{processInstanceId}", method=RequestMethod.GET)
public ResponseEntity<byte[]> displayProcessFile(#PathVariable String processInstanceId) throws UnauthorizedUserAccessException{
Document processFile=null;
try {
processFile = documentService.retrieveProcessFile(Long.parseLong(processInstanceId));
} catch (ProcessFileNotFoundExpection e) {
e.printStackTrace();
}
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.parseMediaType("application/pdf"));
headers.add("content-disposition", "attachment;filename=" + processFile.getDocName());
ResponseEntity<byte[]> response = new ResponseEntity<byte[]>(processFile.getContent(), headers, HttpStatus.OK);
return response;
}

Return File From Resteasy Server

Hi, I wanted to return a file from a resteasy server. For this purpose, I have a link at the client side which is calling a rest service with ajax. I want to return the file in the rest service. I tried these two blocks of code, but both didn't work as I wanted them to.
#POST
#Path("/exportContacts")
public Response exportContacts(#Context HttpServletRequest request, #QueryParam("alt") String alt) throws IOException {
String sb = "Sedat BaSAR";
byte[] outputByte = sb.getBytes();
return Response
.ok(outputByte, MediaType.APPLICATION_OCTET_STREAM)
.header("content-disposition","attachment; filename = temp.csv")
.build();
}
.
#POST
#Path("/exportContacts")
public Response exportContacts(#Context HttpServletRequest request, #Context HttpServletResponse response, #QueryParam("alt") String alt) throws IOException {
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=temp.csv");
ServletOutputStream out = response.getOutputStream();
try {
StringBuilder sb = new StringBuilder("Sedat BaSAR");
InputStream in =
new ByteArrayInputStream(sb.toString().getBytes("UTF-8"));
byte[] outputByte = sb.getBytes();
//copy binary contect to output stream
while (in.read(outputByte, 0, 4096) != -1) {
out.write(outputByte, 0, 4096);
}
in.close();
out.flush();
out.close();
} catch (Exception e) {
}
return null;
}
When I checked from the firebug console, both of these blocks of code wrote "Sedat BaSAR" in response to the ajax call. However, I want to return "Sedat BaSAR" as a file. How can I do that?
Thanks in advance.

There're two ways to to it.
1st - return a StreamingOutput instace.
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response download() {
InputStream is = getYourInputStream();
StreamingOutput stream = new StreamingOutput() {
public void write(OutputStream output) throws IOException, WebApplicationException {
try {
output.write(IOUtils.toByteArray(is));
}
catch (Exception e) {
throw new WebApplicationException(e);
}
}
};
return Response.ok(stream, MediaType.APPLICATION_OCTET_STREAM).header("content-disposition", "attachment; filename=\"temp.csv\"").build();
}
You can return the filesize adding Content-Length header, as the following example:
return Response.ok(stream, MediaType.APPLICATION_OCTET_STREAM).header("content-disposition", "attachment; filename=\"temp.csv\"").header("Content-Length", getFileSize()).build();
But if you don't want to return a StreamingOutput instance, there's other option.
2nd - Define the inputstream as an entity response.
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response download() {
InputStream is = getYourInputStream();
return Response.code(200).entity(is).build();
}