使用restful-api插件上传Grails文件

Question

我的Config.groovy文件显示：

resource 'ktm-documents' config{
serviceName ='docCompositeService'
// methods = ['list']
representation {
    mediaTypes = ["application/vnd.hedtech.v1+json", "application/json", "multipart/form-data"]
    marshallers{
        jsonBeanMarshaller{
            supports net.hedtech.banner.decorator.DocDecorator
        }
        jsonBeanMarshaller{
            supports net.hedtech.banner.decorator.Indexes
        }
    }
    extractor = new  net.hedtech.banner.extractor.DocExtractor()
}
}

提取器是：

class DocExtractor implements RequestExtractor{
@Override
Map extract(HttpServletRequest request) {
print("========== My EXTRACTOR ========")
MultipartHttpServletRequest mpr
Map responseMap = [:]
print request

try {
   print "Here's abc " + request.getParameter("abc")

   mpr = (MultipartHttpServletRequest) request;
   CommonsMultipartFile file = (CommonsMultipartFile) mpr.getFile("file");


    if (file.isEmpty()) {
        responseMap.put("error","file empty hai")
    } else {
        responseMap.put("file", file)
    }

print responseMap.values()

} catch (Exception e) {
   e.printStackTrace()
}
}
}

当尝试从服务的create（）中的提取器中获取从请求中提取的文件时，我得到“无法获取属性'文件'为null”错误。

服务中的create（）方法：

def create(Map params){

print params
File f = params.file

return ["File Uploaded!"]
}

对此有何想法？