无法从目标c

Question

在我将UIImage转换为JPEG后，我得到了UIImage，现在我又转换成了多部分文件，然后我转到了Spring rest controller 使用post并将该图像存储到我的数据库中。但我在春天会得到null MultipartFile。

 NSMutableURLRequest *request = [[NSMutableURLRequest alloc] 
 initWithURL:[NSURL URLWithString:@"myURL"]];

    NSData *imageData = UIImageJPEGRepresentation(image, 0.5);// image is UIImage

    [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
    [request setHTTPShouldHandleCookies:NO];
    [request setTimeoutInterval:60];
    [request setHTTPMethod:@"POST"];

    NSString *boundary = @"unique-consistent-string";

    // set Content-Type in HTTP header
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
    [request setValue:contentType forHTTPHeaderField: @"Content-Type"];

    // post body
    NSMutableData *body = [NSMutableData data];

    // add params (all params are strings)
    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=%@\r\n\r\n", @"imageCaption"] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"%@\r\n", @"Some Caption"] dataUsingEncoding:NSUTF8StringEncoding]];

    // add image data
    if (imageData) {
        [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=%@; filename=imageName.jpg\r\n", @"imageFormKey"] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[@"Content-Type: image/jpeg\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:imageData];
        [body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
    }

    [body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

    // setting the body of the post to the reqeust
    [request setHTTPBody:body];

    // set the content-length
    NSString *postLength = [NSString stringWithFormat:@"%lu", (unsigned long)[body length]];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];

    NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
    [[session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        NSString *requestReply = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
        NSLog(@"Request reply: %@", requestReply);
    }] resume];

我在目标c中传递了如上图像

 @RequestMapping(value = "/livesessionimage", method = RequestMethod.POST)
 @ResponseBody ResponseEntity<Response<String>> livesessionImageUpload(@RequestBody MultipartFile file) throws Exception{
 System.out.println("-------------"+file.length());// here i'm getting file null

return "";
}