使用angular上传文件：The current request is not a multipart request

Question

今天用angular做文件上传的时候遇到了这个问题，网上的解决方案无非两种

1. post请求
2. Content-Type:multipart/form-data

然而我的问题还是没有解决，查看请求很明显，Content-Type没问题,FormData也没问题。

查看angular请求方式为POST也没问题

this.uploadFile = function () {
    var formData = new FormData();
    formData.append("file", file.files[0]); //文件上传框的name
    return $http({
        method: "post",
        url: "/upload.do",
        data: formData,
        headers: {"Content-Type": undefined},
        transformRequest: angular.identity
    })
}

再看一下Controller的代码

@RequestMapping("/upload")
public ReturnResult upload(MultipartFile file){
    String fullName = file.getOriginalFilename();   //获取文件名
    String extName = fullName.substring(fullName.lastIndexOf(".") + 1); //得到拓展名
    try {
        FastDFSClient client = new FastDFSClient("classpath:config/fdfs_client.conf");
        String fileId = client.uploadFile(file.getBytes(), extName);
        String url = file_server_url + fileId;  //图片的完整地址
        return new ReturnResult(true, url);
    } catch (Exception e) {
        e.printStackTrace();
        return new ReturnResult(false, "上传失败");
    }
}

看起来所有代码都没问题，但还是报了这个错误
Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: The current request is not a multipart request
参数类型不匹配，有没有大佬告诉我哪个环节出了问题，万分感谢！

Answer 1

this.uploadFile = function () {
    var formData = new FormData();
    formData.append("file", file.files[0]); //文件上传框的name
    return $http({
        method: "post",
        url: "/upload.do",
        data: formData,
        headers: {"Content-Type": "multipart/form-data"},
        transformRequest: angular.identity
    })
}