<el-upload class="step_content" drag
         action="string"
         ref="upload"
         :multiple="false"
         :http-request="createAppVersion"
         :data="appVersion"
         :auto-upload="false"
         :limit="1"
         :on-change="onFileUploadChange"
         :on-remove="onFileRemove">
    <i class="el-icon-upload"></i>
    <div class="el-upload__text">将文件拖到此处，或<em>点击上传</em></div>

</el-upload>

 <div class="mgt30">
    <el-button v-show="createAppVisible" :disabled="createAppDisable" type="primary" class="mgt30"
          @click="onSubmitClick">立即创建
    </el-button>
 </div>

....

 onSubmitClick() {
    this.$refs.upload.submit();
   },

   createAppVersion(param) {
    this.globalLoading = true;

    const formData = new FormData();
    formData.append('file', param.file);
    formData.append('appVersion', JSON.stringify(this.appVersion));

    addAppVersionApi(formData).then(res => {
     this.globalLoading = false;
     this.$message({message: '创建APP VERION 成功', type: 'success'});
     this.uploadFinish();
    }).catch(reason => {
     this.globalLoading = false;
     this.showDialog(reason);
    })

   },

const formData = new FormData();
formData.append('file', param.file);
formData.append('appVersion', JSON.stringify(this.appVersion));

 function httpPostMutipartFileAsyn(url, param) {
 return new Promise((resolve, reject) => {
  request({
   url: url,
   headers: {
    'Content-Type': 'multipart/form-data'
   },
   method: 'post',
   data: param
  }).then(response => {
   if (response.data.status.code === 0) {
    resolve(response.data)
   } else {
    reject(response.data.status)
   }
  }).catch(response => {
   reject(response)
  })
 })
}

@PostMapping("/version/add")
  public RestResult addAppVersion(@RequestParam("appVersion") String appVersion,
                  @RequestParam("file") MultipartFile multipartFile) {

    ....
    
    return new RestResult();
  }

    <dependency>
      <groupId>io.github.openfeign.form</groupId>
      <artifactId>feign-form</artifactId>
      <version>3.0.3</version>
    </dependency>

    <dependency>
      <groupId>io.github.openfeign.form</groupId>
      <artifactId>feign-form-spring</artifactId>
      <version>3.0.3</version>
    </dependency>

    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.3</version>
    </dependency>

@FeignClient(name = "resource-client",url = "http://xxxx",path = "resource",configuration = ResourceServiceFeignClient.MultipartSupportConfig.class)
public interface ResourceServiceFeignClient {

  @PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
  Resource upload(@RequestPart("file") MultipartFile file);

  class MultipartSupportConfig {
    @Bean
    public Encoder feignFormEncoder() {
      return new SpringFormEncoder();
    }
  }

}