问题不在你的代码中 - 这是你的要求。您在多部分请求中缺少边界。正如在规范中所说：

多部分实体的Content-Type字段需要一个参数
boundary，用于指定封装边界。
封装边界被定义为完全由两个
连字符（ - ，十进制码45）组成的行，接着是来自Content-Type头部字段的边界
参数值。 / p>

这和的帖子也应该是有帮助的。

I did a POC for spring 3 rest multipart file upload. Its working fine. But when i tried integrating with my application i am facing issues.

It throws following exception:

org.springframework.web.multipart.MultipartException: Could not parse multipart servlet request;
nested exception is org.apache.commons.fileupload.FileUploadException:
the request was rejected because no multipart boundary was found**"

Please let me know if I am wrong in any part of my code.

Beans:

<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
 <property name="order" value="1" />
 <property name="mediaTypes">
 <map>
   <entry key="json" value="application/json" />
   <entry key="xml" value="application/xml" />
   <entry key="file" value="multipart/mixed" />
 </map>
</property>
</bean>
<!-- multipart resolver -->
 <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
  <!-- one of the properties available; the maximum file size in bytes -->
  <property name="maxUploadSize" value="50000000" />
 </bean>

Controller:

@Controller
public class MultipleFilesRecieve {
    @RequestMapping ( value = "/saveMultiple", method = RequestMethod.POST )
        public String save( FileUploadForm uploadForm ) {
        List<MultipartFile> files = uploadForm.getFiles( );
        List<String> fileNames = new ArrayList<String>( );
        if ( null != files && files.size( ) > 0 ) {
            for ( MultipartFile multipartFile : files ) {
                String fileName = multipartFile.getOriginalFilename( );
                fileNames.add( fileName );
            }
        }
        return "multifileSuccess";
    }
}

The problem isn't in your code - it's in your request. You're missing boundary in your multipart request. As it said in specification:

The Content-Type field for multipart entities requires one parameter, "boundary", which is used to specify the encapsulation boundary. The encapsulation boundary is defined as a line consisting entirely of two hyphen characters ("-", decimal code 45) followed by the boundary parameter value from the Content-Type header field.

This and this posts should also be helpful.