在Spring中使用RestTemplate将MultipartFile+String作为请求

Question

在我的Spring Boot应用程序中，我需要将String值与MultipartFile一起作为RequestParam传递。Controller在下面，我将MultipartFile转换为java.io.file，然后在RestTemplate的帮助下将其传递给DAO Controller。

来自Angular的请求将首先命中Upload Controller，然后UploadController是客户端(Java)，它将使用基URL调用服务器svs-ba-dao Controller。csvupload包含基本URL：http://localhost:8082/svs-ba-dao/csvupload？parentpkid=&file=multipartfile

@CrossOrigin
@RestController
public class UploadController {

    private static final Logger log = LogManager.getLogger(UploadController.class);

    @Value("${salama.dao.csvUpload.rest.url}")
    private String csvUpload;
    
    @Autowired
    UploadHelperService uploadHelperService;
    
    @PostMapping(value = "/csvUpload")
    public String csvUpload(@QueryParam("parentPkId") String parentPkId, @RequestParam("file") MultipartFile file ) throws IllegalStateException, IOException{
        
        log.info("Calling csvUpload :" + csvUpload);
        final HttpHeaders requestHeaders = new HttpHeaders();
        requestHeaders.setContentType(MediaType.MULTIPART_FORM_DATA);

        File cnvFile = uploadHelperService.multipartToFile(file,file.getOriginalFilename());
        System.out.println("Converted File Name is -->"+cnvFile.getName());
        final MultiValueMap<String, Object> data = new LinkedMultiValueMap<>();
        
        data.add("parentPkId", parentPkId);
        data.add("file", new FileSystemResource(cnvFile));
        
    HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<MultiValueMap<String, Object>>(data, requestHeaders);
    
        RestTemplate restTemplate = new RestTemplate();
        
        ResponseEntity<String> obj =restTemplate.exchange(csvUpload, HttpMethod.POST,
            requestEntity, String.class);
        
        return obj.getBody();
}
    
    
}

在svs-ba-dao控制器中捕获它，如下所示

@RequestMapping(value="/csvUpload", method=RequestMethod.POST)
    public String csvUpload(@RequestParam String parentPkId, @RequestParam MultipartFile file) throws IOException {
        log.info("Entered method csvUpload() of svs-ba-dao.class");
        return uploadService.csvUpload(parentPkId,file);
    }

我已将这些属性包含到应用程序的application.properties文件中:spring.servlet.multipart.maxfilesize=1MBspring.servlet.multipart.maxrequestsize=1MB

因此，我启动应用程序并调用生成POST请求的/csvupload。我得到了低于误差。

Converted File Name is -->testInput_TxnMpMotSlv.csv
2019-01-24T15:12:41,217 ERROR [[localhost].[/svs-ba-dao].[dispatcherServlet]] [http-nio-8085-exec-2] Servlet.service() for servlet [dispatcherServlet] in context with path [/svs-ba-dao] threw exception [Request processing failed; nested exception is org.springframework.web.client.HttpServerErrorException: 500 null] with root cause
org.springframework.web.client.HttpServerErrorException: 500 null
    at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:97) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:79) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at org.springframework.web.client.ResponseErrorHandler.handleError(ResponseErrorHandler.java:63) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:766) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:724) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:680) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:600) ~[spring-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]
    at com.svs-ba-dao.controller.UploadController.csvUpload(UploadController.java:59) ~[classes/:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_192]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_192]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_192]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_192]

resttemplate中存在错误，因为它取null，但是调用resttemplate的语法方法是正确的，因为我没有得到任何错误。通过传递requestparam值，我是否正确地调用了基URL.即parentpkid=？&file=multipartfile

http：//localhost:8082/svs-ba-dao/csvupload？parentpkid=&file=multipartfile
老实说，我以前没有做过这方面的工作。如果我做错了，欢迎任何线索或改正。提前致谢

Answer 1

在这里我发现了我错的地方

csvUpload将保存应在rest模板中传递的URL

 @Value("${salama.dao.csvUpload.rest.url}")
        private String csvUpload;

我发现从UploadController发送的基本URL：即csvUploadhttp://localhost:8082/svs-ba-dao/csvUpload？parentpkid=&file=multipartfile错误。

以下是我更新的基本URL:http://localhost:8082/svs-ba-dao/csvupload？parentpkid=&file=