如何使用 Postman 从 Spring REST 服务下载 PDF

Question

我有一个基于 Spring 的 Rest 服务，它提供 PDF 作为响应。使用下面的代码，我可以在邮递员中将 PDF 内容作为二进制值获取。我的问题是在调用服务时将其作为附件下载。

要实现这一点，我需要对代码或客户端进行任何更改。

@GetMapping(value="/getUserpdf")
    public ResponseEntity<Resource> getUserInfo(@RequestHeader(name="reqHeader") Map<String, String> reqHeader,
                                                  @RequestParam(name="userId",required=true) String userId){

        MetaInfo metaInfo = getHeaderValues(reqHeader);

        //To get Actual PDF content as Bytes
        byte[] pdfBytes = getUserPdfService.getUserInfo(metaInfo,userId);

        ByteArrayResource resource = new ByteArrayResource(pdfBytes);

        HttpHeaders headers = new HttpHeaders();
        headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
        headers.add("Pragma", "no-cache");
        headers.add("Expires", "0");
        headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=UserInfo.pdf");



        return ResponseEntity
                      .ok()
                      .headers(headers)
                      .contentLength(pdfBytes.length)
                      .contentType(MediaType.parseMediaType("application/octet-stream")).body(resource);
    }

我也注册了我的转换器

@Bean
    public HttpMessageConverters customConverters() {
        ByteArrayHttpMessageConverter arrayHttpMessageConverter = new ByteArrayHttpMessageConverter();
        return new HttpMessageConverters(arrayHttpMessageConverter);
    }

Answer 1

这是一个例子：

@GetMapping("/getUserpdf/{id}")
    @CrossOrigin
    @ResponseBody
    public ResponseEntity<InputStreamResource> downloadFile(@PathVariable(required = true, value = "id") Long id,@RequestParam(name="userId",required=true) String userId,HttpServletRequest request) throws IOException {

        //To get Actual PDF content as Bytes
        byte[] pdfBytes = getUserPdfService.getUserInfo(id,userId);
        if (Objects.nonNull(pdfBytes)) {
            String fileName = "UserInfo.pdf";
            MediaType mediaType = MediaType.parseMediaType("application/pdf");
            File file = new File(fileName);
            FileUtils.writeByteArrayToFile(file, pdfBytes); //org.apache.commons.io.FileUtils
            InputStreamResource resource = new InputStreamResource(new FileInputStream(file));

            return ResponseEntity.ok()
                    // Content-Disposition
                    .header(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + file.getName())
                    // Content-Type
                    .contentType(mediaType)
                    // Contet-Length
                    .contentLength(file.length()) //
                    .body(resource);
        } else {
            throw ResponseEntity.notFound().build();
        }
    }

注意：我对 mediaType 不满意，但您可以确认它是否正常！