如何将spring MVC控制器的请求数据管道化到spring RestTemplate

Question

我有一个Spring MVC应用程序，它从UI（multiform和json）获取请求，并且必须使用Spring RestTemplate将这些数据发布到另一个微服务。在json内容类型的情况下，将请求作为字符串复制到RestTemplate可以很好地工作，但在Multipart的情况下似乎不起作用。

这是我的示例代码

Spring MVC控制器：

@Controller
public class MvcController {

  @RequestMapping(value = "/api/microservice",  method = RequestMethod.POST)
  public ResponseEntity<?> callMicroservice(HttpServletRequest request) throws Exception {
      RestTemplate rest = new RestTemplate();
      String payload = IOUtils.toString(request.getReader());
      HttpHeaders headers = new HttpHeaders();
      headers.add("Content-Type", request.getHeader("Content-Type"));
      HttpEntity<String> requestEntity = new HttpEntity<String>(payload, headers);
      return rest.exchange("https://remote.micrservice.com/api/backendservice", HttpMethod.POST, requestEntity, String.class);    
  }
}

@Controller
public class RestController {

  @RequestMapping(value = "/api/backendservice",  method = RequestMethod.POST)
  public @ResponseBody Object createService(@RequestParam(value = "jsondata") String jsondata,
        @RequestParam(value = "email") String email,@RequestParam(value = "xsltFile", required = false) MultipartFile xsltFile,
        HttpServletRequest request) {
      // process jsondata
      // process xsltFile
      // send response
  }
}

String payload = IOUtils.toString(request.getReader());

取而代之的是，我如何将请求数据按原样发送到RestTemplate请求，以便它同时适用于string和Multipart。如果你看MvcController签名，我不知道用户会在某个时候发送什么细节，我也不知道什么是微服务签名。我只需要在MvcController和RestTemplate请求之间管道化数据。

Answer 1

@RequestMapping(value = "/api/microservice",  method = RequestMethod.POST)
  public ResponseEntity<?> callMicroservice(HttpServletRequest request) throws Exception {
      RestTemplate rest = new RestTemplate();
        LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
        map.add("jsondata", yourjsondata);
        map.add("email", youremail);
        map.add("xsltFile", new ClassPathResource(file));
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);

        HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new    HttpEntity<LinkedMultiValueMap<String, Object>>(
                            map, headers);
        ResponseEntity<String > result = template.get().exchange(
                            contextPath.get() + path, HttpMethod.POST, requestEntity,
                            String.class);

}