[FIXED] HttpServletResponse.addHeader() and setHeader() not working in Spring Controller

Issue

I'm trying to build a small web application using spring-mvc,spring-boot and spring security. Only one controller is used and one of the service end-point is to let user download a docx file generated by the web application. My logic code works well, the problem is that when I want to add Headers to HttpServletResponse, addHeader() and setHeader() don't work, I just want to specify a name for the download file. I printed some logs and got no clue why this is not working.

Here is part code of my controller:

@Controller
public class ImportExportController {

    private final static Logger LOGGER = LoggerFactory.getLogger(ImportExportController.class);

    @Autowired
    private WordProcessor wordProcessor;

    @RequestMapping("/export")
    public void export(@RequestParam(value = "domainName", required = true) String domainName,
                       @RequestParam(value = "projectName", required = true) String projectName,
                       @RequestParam(value = "testFolderId", required = true) int testFolderId,
                       HttpServletRequest request, HttpServletResponse response) {

        String exportedFileName = "exportedTC_" + domainName + "_" + projectName + "_"
                + Integer.toString(testFolderId) + ".docx";

        try {
            extendExpiredALMSession();
            SaveToZipFile saver = wordProcessor.ExportToWord(domainName, projectName,
                                                             Integer.toString(testFolderId));
            saver.save(response.getOutputStream());
            response.setContentType("application/vnd.openxmlformats-officedocument.wordprocessingml.document");
            LOGGER.info("exportedFileName: " + exportedFileName);
            LOGGER.info("contains: " + response.containsHeader("Content-Disposition"));
            response.addHeader("Content-Disposition", "attachment; filename=\"" + exportedFileName + "\"");
            for (String name : response.getHeaderNames()) {
                LOGGER.info("Header: " + name);
            }
            LOGGER.info("Date Header:" + response.getHeader("Date"));
            LOGGER.info("Content-Disposition header: " + response.getHeader("Content-Disposition"));
            LOGGER.info("ContentType: " + response.getHeader("ContentType"));
            response.flushBuffer();
        } catch (RequestFailureException | RESTAPIException | InvalidDataException | UnLoginException
                | UnAuthorizedOperationException | IOException | Docx4JException | URISyntaxException e) {
            e.printStackTrace();
        }
    }
}

And here are logs I got, you can see that Header "Content-Disposition" and "ContentType" are both null.

2014-05-07_13:35:05.646 INFO  c.c.p.a.w.w.ImportExportController - exportedFileName: exportedTC_DEFAULT_JIRA_Test_CPL5_4520.docx
2014-05-07_13:35:05.646 INFO  c.c.p.a.w.w.ImportExportController - contains: false
2014-05-07_13:35:05.646 INFO  c.c.p.a.w.w.ImportExportController - Header: X-Content-Type-Options
2014-05-07_13:35:05.646 INFO  c.c.p.a.w.w.ImportExportController - Header: X-XSS-Protection
2014-05-07_13:35:05.646 INFO  c.c.p.a.w.w.ImportExportController - Header: Cache-Control
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Header: Pragma
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Header: Expires
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Header: X-Frame-Options
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Header: X-Application-Context
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Header: Transfer-Encoding
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Header: Date
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Date Header:Wed, 07 May 2014 17:35:05 GMT
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - Content-Disposition header: null
2014-05-07_13:35:05.647 INFO  c.c.p.a.w.w.ImportExportController - ContentType: null

Thanks for reading. Any help will be appreciated.

Solution

It turns out to be Spring Controller have default header for all the responses so that I have access to the response body but not the headers. To set the HttpHeaders, return a HttpEntity will work. Solution code below:

  @RequestMapping(value = "/export", method = RequestMethod.GET, produces = "application/vnd.openxmlformats-officedocument.wordprocessingml.document")
    public HttpEntity<byte[]> export(@RequestParam(value = "domainName", required = true) String domainName,
                                     @RequestParam(value = "projectName", required = true) String projectName,
                                     @RequestParam(value = "testFolderId", required = true) int testFolderId) {

    String exportedFileName = "exportedTC_" + domainName + "_" + projectName + "_"
            + Integer.toString(testFolderId) + ".docx";
    SaveToZipFile saver = null;
    ByteArrayOutputStream out = null;
    HttpHeaders responseHeaders = null;
    byte[] documentBody = null;
    try {
        extendExpiredALMSession();
        saver = wordProcessor.ExportToWord(domainName, projectName, Integer.toString(testFolderId));
        out = new ByteArrayOutputStream();
        saver.save(out);
        responseHeaders = new HttpHeaders();
        responseHeaders.add("Content-Type",
                            "application/vnd.openxmlformats-officedocument.wordprocessingml.document");
        responseHeaders.add("Content-Disposition", "attachment; filename=\"" + exportedFileName + "\"");
        documentBody = out.toByteArray();
    } catch (RequestFailureException | RESTAPIException | InvalidDataException | UnLoginException
            | UnAuthorizedOperationException | IOException | Docx4JException | URISyntaxException e) {
        e.printStackTrace();
    }
    return new HttpEntity<byte[]>(documentBody, responseHeaders);
    }

This works for me.

Answered By - David Z.
Answer Checked By - Timothy Miller (JavaFixing Admin)