使用DispatcherServlet

@Configuration
public class WebConfig {   
    @Bean
    public ServletRegistrationBean apiV1ServletBean(WebApplicationContext wac) {
        DispatcherServlet ds = new DispatcherServlet(wac);
        ServletRegistrationBean bean = new ServletRegistrationBean(ds, "/*");
        bean.setName("xxx");
       bean.addUrlMappings("/xxx/*");
       return bean;
   }

}

MultipartFile接收不到文件
@RequestMapping(method = RequestMethod.POST)
    public Response<String> site(@RequestParam("file") MultipartFile file, String userId, HttpServletRequest request) {

}

错误报告：
Required request part 'file' is not present