如何在Spring RestController中下载excel文件

Question

我正在使用Apache POI生成. xlsx文件。

我想从Spring controller返回该文件。以下是我到目前为止所做的：

控制器：

@RequestMapping(method = RequestMethod.GET)
    public HttpEntity<byte[]> createExcelWithTaskConfigurations(HttpServletResponse response) throws IOException {
        byte[] excelContent = excelService.createExcel();

        HttpHeaders header = new HttpHeaders();
        header.setContentType(new MediaType("application", "vnd.openxmlformats-officedocument.spreadsheetml.sheet"));
        header.set(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=my_file.xls");
        header.setContentLength(excelContent.length);

        return new HttpEntity<>(excelContent, header);
    }

是否可以从rest控制器返回实际的excel文件，以便用户可以将其下载到计算机上？至于现在控制器返回字节[]，但我想返回它的实际文件。我怎样才能做到这一点？

Answer 1

这是我用来下载txt文件的工作代码。Excel文件也应该如此。

@GetMapping("model")
public void getDownload(HttpServletResponse response) throws IOException {


    InputStream myStream = your logic....

    // Set the content type and attachment header.  for txt file
    response.addHeader("Content-disposition", "inline;filename=sample.txt");
    response.setContentType("txt/plain");

    // xls file
    response.addHeader("Content-disposition", "attachment;filename=sample.xls");
    response.setContentType("application/octet-stream");

    // Copy the stream to the response's output stream.
    IOUtils.copy(myStream, response.getOutputStream());
    response.flushBuffer();
}

Answer 2

感谢@JAR. JAR. Beans。这是链接：从Spring控制器下载文件

@RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
@ResponseBody 
public FileSystemResource getFile(@PathVariable("file_name") String fileName) {
    return new FileSystemResource(myService.getFileFor(fileName)); 
}

Answer 3

您可以使用ByteArrayResources作为文件下载。以下是您修改后的代码片段

    @GetMapping(value="/downloadTemplate")
    public HttpEntity<ByteArrayResource> createExcelWithTaskConfigurations() throws IOException {
        byte[] excelContent = excelService.createExcel();

        HttpHeaders header = new HttpHeaders();
        header.setContentType(new MediaType("application", "force-download"));
        header.set(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=my_file.xlsx");


        return new HttpEntity<>(new ByteArrayResource(excelContent), header);
    }

如果您尝试使用apache poi生成excel，请在下面找到代码片段

    @GetMapping(value="/downloadTemplate")
    public ResponseEntity<ByteArrayResource> downloadTemplate() throws Exception {
        try {
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            XSSFWorkbook workbook = createWorkBook(); // creates the workbook
            HttpHeaders header = new HttpHeaders();
            header.setContentType(new MediaType("application", "force-download"));
            header.set(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=ProductTemplate.xlsx");
            workbook.write(stream);
            workbook.close();
            return new ResponseEntity<>(new ByteArrayResource(stream.toByteArray()),
                    header, HttpStatus.CREATED);
        } catch (Exception e) {
            log.error(e.getMessage());
            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }