How to download PDF from Spring REST service using Postman - spring-boot

Question

I have a Spring based Rest service which gives PDF as response. With my below code I can able to get the PDF content as binary values in my postman. My problem is to download it as attachment when I call the service.
To achieve this do i need to make any change in code or in Client.
#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);
}
Also I have registered my Converter
#Bean
public HttpMessageConverters customConverters() {
ByteArrayHttpMessageConverter arrayHttpMessageConverter = new ByteArrayHttpMessageConverter();
return new HttpMessageConverters(arrayHttpMessageConverter);
}

Answer 1

Here is an example :
#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();
}
}
NB: i am not sur about the mediaType but you can confirm if it's ok !