为什么网关微服务的多部分表单"restream"不起作用，并且未重新发送附加文件？

Question

我在网关微服务中有一个控制器，它接受MultipartFile并重新发送到它后面的服务

@PostMapping
public ResponseEntity upload(@ApiParam(name = "file", value = "File", required = true) MultipartFile file)
throws BaseException {
if (Objects.isNull(file)){
throw new CheckFieldException("file", MultipartFile.class);
}
if (megabyte * maxFileSize - file.getSize() < 0){
return ResponseEntity.accepted().body(new DocumentResponseDTO(false, "File size exceeds " + maxFileSize + "MB"));
}
DiscoveryConfig.CashTracking config = discoveryConfig.getCashTracking();
UriComponents uriStatementUpload = UriComponentsBuilder.newInstance().scheme(config.getScheme())
.host(config.getHost()).port(config.getPort()).path(config.getExcelNominalOperationsPath()).build(true);
try {
HttpEntity<byte[]> fileEntity = new HttpEntity(file.getBytes());
ResponseEntity<DocumentResponseDTO> entity = restTemplate.postForEntity(uriStatementUpload.toUri(), fileEntity, DocumentResponseDTO.class);
return entity;
} catch (HttpClientErrorException e) {
return ResponseEntity.status(e.getStatusCode()).body(e.getResponseBodyAsString());
} catch (IOException e) {
return ResponseEntity.status(500).body("IOException while getting bytes stream from file");
}
}

在CashTracking服务中也有这样的文件上传:

@PostMapping(value = "/upload")
public ResponseEntity uploadExcelNominalOperationsFile(@ApiParam(name = "file", value = "File", required = true) MultipartFile file) throws IOException {
try (InputStream is = file.getInputStream()) {
log.info("Processing incoming Excel file with nominal operations");
Workbook workbook = new XSSFWorkbook(is);
log.info("Processing workbook");
Sheet sheet = workbook.getSheetAt(0);
log.info("Processing the first sheet");
List<NominalOperationVO> nominalOperationVOs = new ArrayList<>();
List<String> fileHeaders = new ArrayList<>();

当文件真正上传到网关服务时，其背后的服务开始处理文件上传，但MultipartFile file为空。我已经明确地把它放在我发送给网关后面的服务的实体中，问题是，如果它是空的，我做错了什么?如果我直接上传到那个微服务，它会正确地处理请求。

Answer 1

我错过的主要东西是把Http头每个特定的多部分表单的部分。它们应该与发送给网关服务的内容相同。

public ResponseEntity upload(@ApiParam(name = "file", value = "Файл", required = true) MultipartFile file)
throws BaseException {
if (Objects.isNull(file)){
throw new CheckFieldException("file", MultipartFile.class);
}
if (megabyte * maxFileSize - file.getSize() < 0){
return ResponseEntity.accepted().body(new DocumentResponseDTO(false, "File size exceeds " + maxFileSize + "MB"));
}
DiscoveryConfig.CashTracking config = discoveryConfig.getCashTracking();
UriComponents uriStatementUpload = UriComponentsBuilder.newInstance().scheme(config.getScheme())
.host(config.getHost()).port(config.getPort()).path(config.getExcelNominalOperationsPath()).build(true);
try {
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
MultipartBodyBuilder multipartBodyBuilder = new MultipartBodyBuilder();
//here is the really needed stuff with 2 headers
Resource resource = new ByteArrayResource(file.getBytes());
multipartBodyBuilder.part("file", resource)
.header("Content-Type",file.getContentType())
.header("Content-Disposition","form-data; name="file"; filename=""+file.getOriginalFilename()+""");
// multipart/form-data request body
MultiValueMap<String, HttpEntity<?>> body = multipartBodyBuilder.build();
HttpEntity<MultiValueMap<String, HttpEntity<?>>> requestEntity
= new HttpEntity<>(body, headers);
ResponseEntity<DocumentResponseDTO> entity = restTemplate.postForEntity(uriStatementUpload.toUri(), requestEntity, DocumentResponseDTO.class);
return entity;
} catch (HttpClientErrorException e) {
return ResponseEntity.status(e.getStatusCode()).body(e.getResponseBodyAsString());
} catch (IOException e) {
return ResponseEntity.status(500).body("IOException while getting bytes stream from file");
}
}