SpringCloud中各服务之间文件上传处理说明

在SpringCloud中文件上传可以采用FeignForm或者直接HttpClient方式进行处理，如下所示

 

一、用FeignClient进行文件上传

1.1、需要增加对应的pom文件

        
            io.github.openfeign.form
            feign-form
        
        
            io.github.openfeign.form
            feign-form-spring
        

1.2、定义服务端的上传接口跟普通springMVC文件上传接口类同:

    @PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    public Result uploadFile(
            @RequestPart("file") MultipartFile file,
            @RequestParam("param1") String param1,
            @RequestParam(value = "param2",required = false) String param2) {

需要指定对应的consumes为MediaType.MULTIPART_FORM_DATA_VALUE，如果是多个参数，则需要指定file参数为@RequestPart("file") MultipartFile file

 

1.3 增加供客户端调用的Feign接口

@FeignClient(value = "${service_name}",configuration = UploadClientConfiguration.class ,contextId = "${service_name}ClientFileApi")
public interface ClientFileApi {
       
     @PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     public Result uploadFile(
            @RequestPart("file") MultipartFile file,
            @RequestParam("param1") String param1,
            @RequestParam(value = "param2",required = false) String param2) {

 

public class UploadClientConfiguration {

    /**
     * 此处注入的是： ObjectFactory
     */
    @Autowired
    private ObjectFactory messageConverters;

    @Bean
    public Encoder feignEncoder() {
        return new SpringFormEncoder(new SpringEncoder(messageConverters));
    }
}

需要注意的是FeignClient接口中的configuration必须为FeignForm对应的配置UploadClientConfiguration

 

1.4 客户端调用，直接接收到文件后，进行转发即可，如下所示:

@Resource
ClientFileApi clientFileApi;

@RequestMapping(value = "/upload", method = RequestMethod.POST)
public ResponseEntity  uploadFile(
      @RequestParam("file") MultipartFile mpfile){DiskFileItem fileItem =(DiskFileItem) new DiskFileItemFactory().createItem("featureFile",MediaType.ALL.toString(),true, featureFile.getOriginalFilename());
       try (InputStream input = featureFile.getInputStream(); OutputStream os = fileItem.getOutputStream()) {
          IOUtils.copy(input, os);
       } catch (Exception e) {
          throw new IllegalArgumentException("Invalid file: " + e, e);
       } 
     MultipartFile file = new CommonsMultipartFile(fileItem); 
         clientFileApi.upload(file,"","");



}

在使用FeignClient进行文件上传时，报如下的错误：

org.springframework.web.multipart.support.MissingServletRequestPartException: Required request part 'file' is not present

需要服务器端配置@EnabledMVc，并且配置上传文件相关属性

如下所示:

/***
 *
 */
@Configuration
@EnableWebMvc
public class WebMvcConfiguration implements WebMvcConfigurer {
    @Bean
    public MultipartResolver multipartResolver() {
        CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
        multipartResolver.setMaxInMemorySize(10240);
        multipartResolver.setMaxUploadSizePerFile(10*1024*1024);
        multipartResolver.setResolveLazily(false);
        return multipartResolver;
    }
}

 

二、直接用RestTemplate进行上传即可

 

/***
     * 进行文件上传处理
     * @param file
     * @param param1
     * @param param2
     * @return
     */
    public boolean uploadFile(MultipartFile file, String param1, String param2)
    {
        String url="http://"+servicename"/file/upload"; 
        try {
            //return restTemplate.
            MultiValueMap param = new LinkedMultiValueMap<>();
            param.add("param1", param1);
            param.add("param2", param2); 
            param.add("files",file.getResource());
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.MULTIPART_FORM_DATA);
            HttpEntity> httpEntity = new HttpEntity<>(param, headers);

           
            ResponseEntity re = restTemplate.postForEntity(url,httpEntity,String.class);