java - React excel file download corrupt

Question

Im trying to download an Excel file in Reactjs by calling a Spring REST endpoint but I'm running into issues with a corrupt file.

React call...

getFile(){
    axios.get('get/download')
        .then((response) => {
            var blob = new Blob([response.data], {type:'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'});
            filesaver.saveAs(blob, "excel.xlsx");
        });
}

Spring controller....

@RequestMapping(value = "/download", method = RequestMethod.GET)
    public void downloadExcelFile(final HttpServletResponse response) throws IOException {
        response.setHeader("Content-Encoding", "UTF-8");
        response.setHeader("Content-Disposition", "attachment; filename="file.xlsx");
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");

        final File xls = service.createExcelFile(response);

        final FileInputStream in = new FileInputStream(xls);
        final OutputStream out = response.getOutputStream();

        final byte[] buffer = new byte[8192];
        int length;

        while ((length = in.read(buffer)) > 0) {
            out.write(buffer, 0, length);
        }
        in.close();
        out.close();
    }

Service...

 public File createExcelFile(final HttpServletResponse response) {
     XSSFWorkbook xssfWorkbook = null;
     final File xls = new File("excel.xlsx");
        try {
            final FileOutputStream fos = new FileOutputStream(xls);

            xssfWorkbook = new XSSFWorkbook();
            //setup excel file...
            xssfWorkbook.write(fos);
            xssfWorkbook.close();
       }
       catch (final Exception e) {
           LOGGER.error(String.format("Something went wrong"));
       }
    return xls;
 }

When I execute the above code I get an excel file o.k...but looking at response.data looks like...

"PKs??J_rels/.rels???j?0??}??{?1F?^??2??l%1I,c?[?

Tring to open the file I get...Could not open file due to unreadable data. Opening the file create on the server is ok

Any ideas welcome

Cheers

Answer 1

You just have to add response type to the axios request:

responseType: 'arraybuffer'

In my application following function downloads excel file:

function exportIssues() {
  axios.get('/issues/export', { responseType: 'arraybuffer' })
    .then((response) => {
      var blob = new Blob([response.data], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
      fileSaver.saveAs(blob, 'fixi.xlsx');
    });
}