JSF csv download [duplicate] - jsf

Is there any way of providing a file download from a JSF backing bean action method?
I have tried a lot of things. Main problem is that I cannot figure how to get the OutputStream of the response in order to write the file content to. I know how to do it with a Servlet, but this cannot be invoked from a JSF form and requires a new request.
How can I get the OutputStream of the response from the current FacesContext?

Introduction
You can get everything through ExternalContext. In JSF 1.x, you can get the raw HttpServletResponse object by ExternalContext#getResponse(). In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream() without the need to grab the HttpServletResponse from under the JSF hoods.
On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.
Most important part is to call FacesContext#responseComplete() to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException with a message like getoutputstream() has already been called for this response when the JSF implementation calls getWriter() to render HTML.
Turn off ajax / don't use remote command!
You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink> and <h:commandButton>. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.
In case you're using e.g. PrimeFaces <p:commandXxx>, then you need to make sure that you explicitly turn off ajax via ajax="false" attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" /> in the command component.
Generic JSF 2.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();
ec.responseReset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
ec.setResponseContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ExternalContext#getMimeType() for auto-detection based on filename.
ec.setResponseContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = ec.getResponseOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Generic JSF 1.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
response.setContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = response.getOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Common static file example
In case you need to stream a static file from the local disk file system, substitute the code as below:
File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();
// ...
Files.copy(file.toPath(), output);
Common dynamic file example
In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output there where the API being used expects an OutputStream.
E.g. iText PDF:
String fileName = "dynamic.pdf";
String contentType = "application/pdf";
// ...
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
// Build PDF content here.
document.close();
E.g. Apache POI HSSF:
String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";
// ...
HSSFWorkbook workbook = new HSSFWorkbook();
// Build XLS content here.
workbook.write(output);
workbook.close();
Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.
Utility method
If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile() methods taking either a File, or an InputStream, or a byte[], and specifying whether the file should be downloaded as an attachment (true) or inline (false).
public void download() throws IOException {
Faces.sendFile(file, true);
}
Yes, this code is complete as-is. You don't need to invoke responseComplete() and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.

public void download() throws IOException
{
File file = new File("file.txt");
FacesContext facesContext = FacesContext.getCurrentInstance();
HttpServletResponse response =
(HttpServletResponse) facesContext.getExternalContext().getResponse();
response.reset();
response.setHeader("Content-Type", "application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=file.txt");
OutputStream responseOutputStream = response.getOutputStream();
InputStream fileInputStream = new FileInputStream(file);
byte[] bytesBuffer = new byte[2048];
int bytesRead;
while ((bytesRead = fileInputStream.read(bytesBuffer)) > 0)
{
responseOutputStream.write(bytesBuffer, 0, bytesRead);
}
responseOutputStream.flush();
fileInputStream.close();
responseOutputStream.close();
facesContext.responseComplete();
}

This is what worked for me:
public void downloadFile(String filename) throws IOException {
final FacesContext fc = FacesContext.getCurrentInstance();
final ExternalContext externalContext = fc.getExternalContext();
final File file = new File(filename);
externalContext.responseReset();
externalContext.setResponseContentType(ContentType.APPLICATION_OCTET_STREAM.getMimeType());
externalContext.setResponseContentLength(Long.valueOf(file.lastModified()).intValue());
externalContext.setResponseHeader("Content-Disposition", "attachment;filename=" + file.getName());
final HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
FileInputStream input = new FileInputStream(file);
byte[] buffer = new byte[1024];
final ServletOutputStream out = response.getOutputStream();
while ((input.read(buffer)) != -1) {
out.write(buffer);
}
out.flush();
fc.responseComplete();
}

This is my solution, an extension of BalusC's answer
public static void download(
ByteArrayOutputStream baos,
String downloadFileName,
String contentType
) {
FacesContext context = FacesContext.getCurrentInstance();
ExternalContext externalContext = context.getExternalContext();
externalContext.responseReset();
HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
response.reset();
response.setContentType(contentType);
response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
Integer size = baos.size();
response.setHeader("Content-Length", size.toString());
response.setHeader(
"Content-Disposition",
"attachment; filename=\"" + downloadFileName + "\""
);
try {
try (OutputStream responseOs = response.getOutputStream()) {
baos.writeTo(responseOs);
}
}
catch (IOException e) {
throw new IOUncheckedException(e);
}
context.responseComplete();
}

here is the complete code snippet http://bharatonjava.wordpress.com/2013/02/01/downloading-file-in-jsf-2/
#ManagedBean(name = "formBean")
#SessionScoped
public class FormBean implements Serializable
{
private static final long serialVersionUID = 1L;
/**
* Download file.
*/
public void downloadFile() throws IOException
{
File file = new File("C:\\docs\\instructions.txt");
InputStream fis = new FileInputStream(file);
byte[] buf = new byte[1024];
int offset = 0;
int numRead = 0;
while ((offset < buf.length) && ((numRead = fis.read(buf, offset, buf.length -offset)) >= 0))
{
offset += numRead;
}
fis.close();
HttpServletResponse response =
(HttpServletResponse) FacesContext.getCurrentInstance()
.getExternalContext().getResponse();
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=instructions.txt");
response.getOutputStream().write(buf);
response.getOutputStream().flush();
response.getOutputStream().close();
FacesContext.getCurrentInstance().responseComplete();
}
}
You may change the file reading logic in case you want file to get generated at runtime.

Related

How to download excel file using JSF and Java [duplicate]

Is there any way of providing a file download from a JSF backing bean action method?
I have tried a lot of things. Main problem is that I cannot figure how to get the OutputStream of the response in order to write the file content to. I know how to do it with a Servlet, but this cannot be invoked from a JSF form and requires a new request.
How can I get the OutputStream of the response from the current FacesContext?
Introduction
You can get everything through ExternalContext. In JSF 1.x, you can get the raw HttpServletResponse object by ExternalContext#getResponse(). In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream() without the need to grab the HttpServletResponse from under the JSF hoods.
On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.
Most important part is to call FacesContext#responseComplete() to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException with a message like getoutputstream() has already been called for this response when the JSF implementation calls getWriter() to render HTML.
Turn off ajax / don't use remote command!
You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink> and <h:commandButton>. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.
In case you're using e.g. PrimeFaces <p:commandXxx>, then you need to make sure that you explicitly turn off ajax via ajax="false" attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" /> in the command component.
Generic JSF 2.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();
ec.responseReset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
ec.setResponseContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ExternalContext#getMimeType() for auto-detection based on filename.
ec.setResponseContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = ec.getResponseOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Generic JSF 1.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
response.setContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = response.getOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Common static file example
In case you need to stream a static file from the local disk file system, substitute the code as below:
File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();
// ...
Files.copy(file.toPath(), output);
Common dynamic file example
In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output there where the API being used expects an OutputStream.
E.g. iText PDF:
String fileName = "dynamic.pdf";
String contentType = "application/pdf";
// ...
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
// Build PDF content here.
document.close();
E.g. Apache POI HSSF:
String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";
// ...
HSSFWorkbook workbook = new HSSFWorkbook();
// Build XLS content here.
workbook.write(output);
workbook.close();
Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.
Utility method
If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile() methods taking either a File, or an InputStream, or a byte[], and specifying whether the file should be downloaded as an attachment (true) or inline (false).
public void download() throws IOException {
Faces.sendFile(file, true);
}
Yes, this code is complete as-is. You don't need to invoke responseComplete() and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.
public void download() throws IOException
{
File file = new File("file.txt");
FacesContext facesContext = FacesContext.getCurrentInstance();
HttpServletResponse response =
(HttpServletResponse) facesContext.getExternalContext().getResponse();
response.reset();
response.setHeader("Content-Type", "application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=file.txt");
OutputStream responseOutputStream = response.getOutputStream();
InputStream fileInputStream = new FileInputStream(file);
byte[] bytesBuffer = new byte[2048];
int bytesRead;
while ((bytesRead = fileInputStream.read(bytesBuffer)) > 0)
{
responseOutputStream.write(bytesBuffer, 0, bytesRead);
}
responseOutputStream.flush();
fileInputStream.close();
responseOutputStream.close();
facesContext.responseComplete();
}
This is what worked for me:
public void downloadFile(String filename) throws IOException {
final FacesContext fc = FacesContext.getCurrentInstance();
final ExternalContext externalContext = fc.getExternalContext();
final File file = new File(filename);
externalContext.responseReset();
externalContext.setResponseContentType(ContentType.APPLICATION_OCTET_STREAM.getMimeType());
externalContext.setResponseContentLength(Long.valueOf(file.lastModified()).intValue());
externalContext.setResponseHeader("Content-Disposition", "attachment;filename=" + file.getName());
final HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
FileInputStream input = new FileInputStream(file);
byte[] buffer = new byte[1024];
final ServletOutputStream out = response.getOutputStream();
while ((input.read(buffer)) != -1) {
out.write(buffer);
}
out.flush();
fc.responseComplete();
}
This is my solution, an extension of BalusC's answer
public static void download(
ByteArrayOutputStream baos,
String downloadFileName,
String contentType
) {
FacesContext context = FacesContext.getCurrentInstance();
ExternalContext externalContext = context.getExternalContext();
externalContext.responseReset();
HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
response.reset();
response.setContentType(contentType);
response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
Integer size = baos.size();
response.setHeader("Content-Length", size.toString());
response.setHeader(
"Content-Disposition",
"attachment; filename=\"" + downloadFileName + "\""
);
try {
try (OutputStream responseOs = response.getOutputStream()) {
baos.writeTo(responseOs);
}
}
catch (IOException e) {
throw new IOUncheckedException(e);
}
context.responseComplete();
}
here is the complete code snippet http://bharatonjava.wordpress.com/2013/02/01/downloading-file-in-jsf-2/
#ManagedBean(name = "formBean")
#SessionScoped
public class FormBean implements Serializable
{
private static final long serialVersionUID = 1L;
/**
* Download file.
*/
public void downloadFile() throws IOException
{
File file = new File("C:\\docs\\instructions.txt");
InputStream fis = new FileInputStream(file);
byte[] buf = new byte[1024];
int offset = 0;
int numRead = 0;
while ((offset < buf.length) && ((numRead = fis.read(buf, offset, buf.length -offset)) >= 0))
{
offset += numRead;
}
fis.close();
HttpServletResponse response =
(HttpServletResponse) FacesContext.getCurrentInstance()
.getExternalContext().getResponse();
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=instructions.txt");
response.getOutputStream().write(buf);
response.getOutputStream().flush();
response.getOutputStream().close();
FacesContext.getCurrentInstance().responseComplete();
}
}
You may change the file reading logic in case you want file to get generated at runtime.

Download dynamically generated Excel spreadsheet in JSF doesn't work [duplicate]

Is there any way of providing a file download from a JSF backing bean action method?
I have tried a lot of things. Main problem is that I cannot figure how to get the OutputStream of the response in order to write the file content to. I know how to do it with a Servlet, but this cannot be invoked from a JSF form and requires a new request.
How can I get the OutputStream of the response from the current FacesContext?
Introduction
You can get everything through ExternalContext. In JSF 1.x, you can get the raw HttpServletResponse object by ExternalContext#getResponse(). In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream() without the need to grab the HttpServletResponse from under the JSF hoods.
On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.
Most important part is to call FacesContext#responseComplete() to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException with a message like getoutputstream() has already been called for this response when the JSF implementation calls getWriter() to render HTML.
Turn off ajax / don't use remote command!
You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink> and <h:commandButton>. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.
In case you're using e.g. PrimeFaces <p:commandXxx>, then you need to make sure that you explicitly turn off ajax via ajax="false" attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" /> in the command component.
Generic JSF 2.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();
ec.responseReset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
ec.setResponseContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ExternalContext#getMimeType() for auto-detection based on filename.
ec.setResponseContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = ec.getResponseOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Generic JSF 1.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
response.setContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = response.getOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Common static file example
In case you need to stream a static file from the local disk file system, substitute the code as below:
File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();
// ...
Files.copy(file.toPath(), output);
Common dynamic file example
In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output there where the API being used expects an OutputStream.
E.g. iText PDF:
String fileName = "dynamic.pdf";
String contentType = "application/pdf";
// ...
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
// Build PDF content here.
document.close();
E.g. Apache POI HSSF:
String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";
// ...
HSSFWorkbook workbook = new HSSFWorkbook();
// Build XLS content here.
workbook.write(output);
workbook.close();
Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.
Utility method
If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile() methods taking either a File, or an InputStream, or a byte[], and specifying whether the file should be downloaded as an attachment (true) or inline (false).
public void download() throws IOException {
Faces.sendFile(file, true);
}
Yes, this code is complete as-is. You don't need to invoke responseComplete() and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.
public void download() throws IOException
{
File file = new File("file.txt");
FacesContext facesContext = FacesContext.getCurrentInstance();
HttpServletResponse response =
(HttpServletResponse) facesContext.getExternalContext().getResponse();
response.reset();
response.setHeader("Content-Type", "application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=file.txt");
OutputStream responseOutputStream = response.getOutputStream();
InputStream fileInputStream = new FileInputStream(file);
byte[] bytesBuffer = new byte[2048];
int bytesRead;
while ((bytesRead = fileInputStream.read(bytesBuffer)) > 0)
{
responseOutputStream.write(bytesBuffer, 0, bytesRead);
}
responseOutputStream.flush();
fileInputStream.close();
responseOutputStream.close();
facesContext.responseComplete();
}
This is what worked for me:
public void downloadFile(String filename) throws IOException {
final FacesContext fc = FacesContext.getCurrentInstance();
final ExternalContext externalContext = fc.getExternalContext();
final File file = new File(filename);
externalContext.responseReset();
externalContext.setResponseContentType(ContentType.APPLICATION_OCTET_STREAM.getMimeType());
externalContext.setResponseContentLength(Long.valueOf(file.lastModified()).intValue());
externalContext.setResponseHeader("Content-Disposition", "attachment;filename=" + file.getName());
final HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
FileInputStream input = new FileInputStream(file);
byte[] buffer = new byte[1024];
final ServletOutputStream out = response.getOutputStream();
while ((input.read(buffer)) != -1) {
out.write(buffer);
}
out.flush();
fc.responseComplete();
}
This is my solution, an extension of BalusC's answer
public static void download(
ByteArrayOutputStream baos,
String downloadFileName,
String contentType
) {
FacesContext context = FacesContext.getCurrentInstance();
ExternalContext externalContext = context.getExternalContext();
externalContext.responseReset();
HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
response.reset();
response.setContentType(contentType);
response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
Integer size = baos.size();
response.setHeader("Content-Length", size.toString());
response.setHeader(
"Content-Disposition",
"attachment; filename=\"" + downloadFileName + "\""
);
try {
try (OutputStream responseOs = response.getOutputStream()) {
baos.writeTo(responseOs);
}
}
catch (IOException e) {
throw new IOUncheckedException(e);
}
context.responseComplete();
}
here is the complete code snippet http://bharatonjava.wordpress.com/2013/02/01/downloading-file-in-jsf-2/
#ManagedBean(name = "formBean")
#SessionScoped
public class FormBean implements Serializable
{
private static final long serialVersionUID = 1L;
/**
* Download file.
*/
public void downloadFile() throws IOException
{
File file = new File("C:\\docs\\instructions.txt");
InputStream fis = new FileInputStream(file);
byte[] buf = new byte[1024];
int offset = 0;
int numRead = 0;
while ((offset < buf.length) && ((numRead = fis.read(buf, offset, buf.length -offset)) >= 0))
{
offset += numRead;
}
fis.close();
HttpServletResponse response =
(HttpServletResponse) FacesContext.getCurrentInstance()
.getExternalContext().getResponse();
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=instructions.txt");
response.getOutputStream().write(buf);
response.getOutputStream().flush();
response.getOutputStream().close();
FacesContext.getCurrentInstance().responseComplete();
}
}
You may change the file reading logic in case you want file to get generated at runtime.

How to fix ExternalContext call that corrupts xls file to download?

I have a method that generates report using jett and that shows the file download dialog for the user:
FacesContext facesContext = FacesContext.getCurrentInstance();
ExternalContext externalContext = facesContext.getExternalContext();
externalContext.responseReset();
externalContext.setResponseContentType("application/vnd.ms-excel");
externalContext.setResponseHeader("Content-Disposition", "attachment; filename=\"" + "precificacao.xls" + "\"");
//map beans omitted
FileOutputStream saida = null;
try {
saida = new FileOutputStream(getClass().getResource("/.").getPath() + "/precificacao.xls");
} catch (IOException e) {
System.err.println(getClass().getResource("/.").getPath() + "/precificacao.xls" + ": " + e.getMessage());
}
InputStream entrada = null;
try {
entrada = new BufferedInputStream(new FileInputStream(getClass().getResource("/template.xls").getFile()));
ExcelTransformer transformer = new ExcelTransformer();
Workbook workbook = transformer.transform(entrada, beans);
workbook.write(saida);
saida.flush();
saida.close();
facesContext.responseComplete();
} //catch ommitted
the downloaded file has already been corrupted, as a text document and without any byte:
print
Before this download dialog routine, xls was generated normally, so I think it's the setResponseContentType that I'm going through the wrong way though I saw the link in the right nomenclature for xls: http://www.iana.org/assignments/media-types
You are aware that you nowhere write the contents of the excel to the response? So the response is effectively empty and hence causes all sorts of weird behaviour.
You even write this yourself:
without any byte
And you have it in the image to...
You would have had the same problem with a PDF, or image or even a plain text file (although that would not have given an error but just be empty)
You would even have had the same problem with a plain servlet. So effectively all your tags (excel, jsf, jsf-2, xls) are not really related to the problem. Narrow things down.
Getting the outputstream from the context and writing the workbook to that stream should fix it.
OutputStream saida = externalContext.getResponseOutputStream();
I solved this way
public void createRelatorioFichaTecnica(Produto produto) throws IOException {
FacesContext facesContext = FacesContext.getCurrentInstance();
ExternalContext externalContext = facesContext.getExternalContext();
externalContext.responseReset();
externalContext.setResponseContentType("application/vnd.ms-excel");
externalContext.setResponseHeader("Content-Disposition", "attachment; filename=\"" + "precificacao.xls" + "\"");
//map beans omitted
OutputStream saida = externalContext.getResponseOutputStream();
try{
InputStream entrada = new BufferedInputStream(new FileInputStream(getClass().getResource("/template.xls").getFile()));
ExcelTransformer transformer = new ExcelTransformer();
Workbook workbook = transformer.transform(entrada, beans);
workbook.write(saida);
saida.flush();
saida.close();
facesContext.responseComplete();
}
//catch omitted
}

Commandlink won't start downloading a file generated with XDocReport [duplicate]

Is there any way of providing a file download from a JSF backing bean action method?
I have tried a lot of things. Main problem is that I cannot figure how to get the OutputStream of the response in order to write the file content to. I know how to do it with a Servlet, but this cannot be invoked from a JSF form and requires a new request.
How can I get the OutputStream of the response from the current FacesContext?
Introduction
You can get everything through ExternalContext. In JSF 1.x, you can get the raw HttpServletResponse object by ExternalContext#getResponse(). In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream() without the need to grab the HttpServletResponse from under the JSF hoods.
On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.
Most important part is to call FacesContext#responseComplete() to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException with a message like getoutputstream() has already been called for this response when the JSF implementation calls getWriter() to render HTML.
Turn off ajax / don't use remote command!
You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink> and <h:commandButton>. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.
In case you're using e.g. PrimeFaces <p:commandXxx>, then you need to make sure that you explicitly turn off ajax via ajax="false" attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" /> in the command component.
Generic JSF 2.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();
ec.responseReset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
ec.setResponseContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ExternalContext#getMimeType() for auto-detection based on filename.
ec.setResponseContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = ec.getResponseOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Generic JSF 1.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
response.setContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.
OutputStream output = response.getOutputStream();
// Now you can write the InputStream of the file to the above OutputStream the usual way.
// ...
fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
Common static file example
In case you need to stream a static file from the local disk file system, substitute the code as below:
File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();
// ...
Files.copy(file.toPath(), output);
Common dynamic file example
In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output there where the API being used expects an OutputStream.
E.g. iText PDF:
String fileName = "dynamic.pdf";
String contentType = "application/pdf";
// ...
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
// Build PDF content here.
document.close();
E.g. Apache POI HSSF:
String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";
// ...
HSSFWorkbook workbook = new HSSFWorkbook();
// Build XLS content here.
workbook.write(output);
workbook.close();
Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.
Utility method
If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile() methods taking either a File, or an InputStream, or a byte[], and specifying whether the file should be downloaded as an attachment (true) or inline (false).
public void download() throws IOException {
Faces.sendFile(file, true);
}
Yes, this code is complete as-is. You don't need to invoke responseComplete() and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.
public void download() throws IOException
{
File file = new File("file.txt");
FacesContext facesContext = FacesContext.getCurrentInstance();
HttpServletResponse response =
(HttpServletResponse) facesContext.getExternalContext().getResponse();
response.reset();
response.setHeader("Content-Type", "application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=file.txt");
OutputStream responseOutputStream = response.getOutputStream();
InputStream fileInputStream = new FileInputStream(file);
byte[] bytesBuffer = new byte[2048];
int bytesRead;
while ((bytesRead = fileInputStream.read(bytesBuffer)) > 0)
{
responseOutputStream.write(bytesBuffer, 0, bytesRead);
}
responseOutputStream.flush();
fileInputStream.close();
responseOutputStream.close();
facesContext.responseComplete();
}
This is what worked for me:
public void downloadFile(String filename) throws IOException {
final FacesContext fc = FacesContext.getCurrentInstance();
final ExternalContext externalContext = fc.getExternalContext();
final File file = new File(filename);
externalContext.responseReset();
externalContext.setResponseContentType(ContentType.APPLICATION_OCTET_STREAM.getMimeType());
externalContext.setResponseContentLength(Long.valueOf(file.lastModified()).intValue());
externalContext.setResponseHeader("Content-Disposition", "attachment;filename=" + file.getName());
final HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
FileInputStream input = new FileInputStream(file);
byte[] buffer = new byte[1024];
final ServletOutputStream out = response.getOutputStream();
while ((input.read(buffer)) != -1) {
out.write(buffer);
}
out.flush();
fc.responseComplete();
}
This is my solution, an extension of BalusC's answer
public static void download(
ByteArrayOutputStream baos,
String downloadFileName,
String contentType
) {
FacesContext context = FacesContext.getCurrentInstance();
ExternalContext externalContext = context.getExternalContext();
externalContext.responseReset();
HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
response.reset();
response.setContentType(contentType);
response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
Integer size = baos.size();
response.setHeader("Content-Length", size.toString());
response.setHeader(
"Content-Disposition",
"attachment; filename=\"" + downloadFileName + "\""
);
try {
try (OutputStream responseOs = response.getOutputStream()) {
baos.writeTo(responseOs);
}
}
catch (IOException e) {
throw new IOUncheckedException(e);
}
context.responseComplete();
}
here is the complete code snippet http://bharatonjava.wordpress.com/2013/02/01/downloading-file-in-jsf-2/
#ManagedBean(name = "formBean")
#SessionScoped
public class FormBean implements Serializable
{
private static final long serialVersionUID = 1L;
/**
* Download file.
*/
public void downloadFile() throws IOException
{
File file = new File("C:\\docs\\instructions.txt");
InputStream fis = new FileInputStream(file);
byte[] buf = new byte[1024];
int offset = 0;
int numRead = 0;
while ((offset < buf.length) && ((numRead = fis.read(buf, offset, buf.length -offset)) >= 0))
{
offset += numRead;
}
fis.close();
HttpServletResponse response =
(HttpServletResponse) FacesContext.getCurrentInstance()
.getExternalContext().getResponse();
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=instructions.txt");
response.getOutputStream().write(buf);
response.getOutputStream().flush();
response.getOutputStream().close();
FacesContext.getCurrentInstance().responseComplete();
}
}
You may change the file reading logic in case you want file to get generated at runtime.

JSF response.setHeader "Content-disposition" no popup

Just starting to learn how to do the download with jsf.
I have looked at couple other related posts. And mainly copy their code, but it seems like I did something wrong.
This is my code
public void download() throws IOException {
FacesContext facesContext = FacesContext.getCurrentInstance();
ExternalContext externalContext = facesContext.getExternalContext();
HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();
response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
response.setHeader("Content-disposition", "attachment;filename=\"001.cvf\""); // The Save As popup magic is done here. You can give it any filename you want, this only won't work in MSIE, it will use current request URL as filename instead.
BufferedInputStream input = null;
BufferedOutputStream output = null;
String content =VCFHandler.getContent(profile.getFriendlist());
response.setHeader("Content-Length", String.valueOf(content.length()));
try {
InputStream stream = new ByteArrayInputStream(content.getBytes("UTF-8"));
input = new BufferedInputStream(stream);
output = new BufferedOutputStream(response.getOutputStream());
byte[] buffer = new byte[10240];
for (int length; (length = input.read(buffer)) > 0;) {
output.write(buffer, 0, length);
}
output.flush();
} finally {
output.close();
input.close();
}
facesContext.responseComplete(); // Important! Else JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}
So I tried this code with debugger in eclipse. When download button is clicked, this method is called (which is what I wanted). But after all steps are finished no popup is shown in my page. Anyone have any suggestions?
BTW the content type is
private final static String contentType="text/x-vcard";
By your problem description, I'm not sure but looks like you're firing the download from an ajax request. Remove the ajax behavior for this request and try again.

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