CODEWITHSUNDEEP
jsf-2primefaces
rwaltz
rwaltz

Reputation: 13

JSF2 download file returns xhtml page source

I've been working on this for hours :

When a button is pressed I need to generate XML and download it to the user. I've tried using primefaces StreamedContent with p:fileDownload - but the only output I ever get is the .xhtml source of the actual page. I can use log statements to display the contents of the the StreamedContent before returning it and I can see my XML code correctly there, but the downloaded file always has the page source instead. (I've tried lots of other ways as well, tied downloading a jpg file, changing the bean to generate a response directly and calling the method through the action in the h:commandButton - always get the page source!).

Here's my .xhtml :

        <p:commandButton value="Create XML Bid/Offer" 
                 id="createXMLButton" 
             disabled="#{portfolioBean.noPortfolioSelected}"
                 ajax="false"
                 icon="ui-icon-arrowthichk-s">
    <p:fileDownload value="#{portfolioBean.order}" />  
</p:commandButton>

(alternate)

    <h:commandButton value="Create XML Bid/Offer" 
    id="createXMLButton" 
    disabled="#{portfolioBean.noPortfolioSelected}"
     ajax="false"
    icon="ui-icon-arrowthichk-s"
    action="#{portfolioBean.download()}" />

And the backing bean methods :

        public StreamedContent getOrder() {
...
}

(alternate)

        public String download() {
...
}

I haven't included the method bodies because I know they return proper XML... it really seems to be something in the JSF magic. Is this a configuration issue or something?

Thanks!

UPDATE OK - I've stripped everything out of my code so it's just this :

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
  xmlns:f="http://java.sun.com/jsf/core"
  xmlns:h="http://java.sun.com/jsf/html"
  xmlns:p="http://primefaces.org/ui">
<h:head>
    <title>Edison Energy Portal</title>
</h:head>
<h:body>
    <h:form id="form">
        <h:commandButton value="Download PDF" action="#{downloadJPG.downloadFile}" />
     </h:form>
</h:body>
</html>

public class DownloadJPG {

// Constants ----------------------------------------------------------------------------------

private static final int DEFAULT_BUFFER_SIZE = 10240; // 10KB.

// Actions ------------------------------------------------------------------------------------

public void downloadFile() throws IOException {

    // Prepare.
    FacesContext facesContext = FacesContext.getCurrentInstance();
    ExternalContext externalContext = facesContext.getExternalContext();
    HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();

    File file = new File("....", "....");
    BufferedInputStream input = null;
    BufferedOutputStream output = null;

    try {
        // Open file.
        input = new BufferedInputStream(new FileInputStream(file), DEFAULT_BUFFER_SIZE);

        // Init servlet response.
        response.reset();
        response.setHeader("Content-Type", "application/pdf");
        response.setHeader("Content-Length", String.valueOf(file.length()));
        response.setHeader("Content-Disposition", "inline; filename=\"...\"");
        output = new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE);

        // Write file contents to response.
        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        int length;
        while ((length = input.read(buffer)) > 0) {
            output.write(buffer, 0, length);
        }

        // Finalize task.
        output.flush();
    } finally {
        // Gently close streams.
        close(output);
        close(input);
    }

    // Inform JSF that it doesn't need to handle response.
    // This is very important, otherwise you will get the following exception in the logs:
    // java.lang.IllegalStateException: Cannot forward after response has been committed.
    facesContext.responseComplete();
}

// Helpers (can be refactored to public utility class) ----------------------------------------

private static void close(Closeable resource) {
    if (resource != null) {
        try {
            resource.close();
        } catch (IOException e) {
            // Do your thing with the exception. Print it, log it or mail it. It may be useful to 
            // know that this will generally only be thrown when the client aborted the download.
            e.printStackTrace();
        }
    }
}

}

I've checked my source image file and it's not corrupt. BalusC's code worked for a single try, then I substituted and XML file for the current jpg, changed the MIME type and nothing has worked since. It's as if something bad has tripped in tomcat and I can't get it out or reset it (I've tried cleaning tomcat through eclipse, manually, even rebooted my box).

this is a real poser.

UPDATE : I've started eclipse clean - no luck. I'm really out of ideas. I have to think this is a configuration somewhere, because I know this code can work (I've seen it).

Upvotes: 1

Views: 3779

Answers (1)

SJuan76
SJuan76

Reputation: 24780

Given that nobody else (not even the mighty BalusC) has answered, I am posting it as a comment.

As how to download, again the BalusC blog. Worth browsing a little if you have spare time.

About the issue with how the browser manages it, it depends of browser handling, anyway most should honor the Content-Disposition header. Change this line in the example

response.setHeader("Content-Disposition", "inline; filename=\"" + getFileName() + "\"");

to

response.setHeader("Content-Disposition", "attachment; filename\"" + getFileName() + "\"");

reference

Upvotes: 1

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