IE8+SpringMVC文件上传防止JSON下载

今天在IE8测试文件上传的时候发现总是提示下载，原因是上传接口返回的是json，通过以下修改就可以保证返回是json并且不会出现下载的情况：

    @RequestMapping(value = "/batchUpload", method = RequestMethod.POST,produces = "text/json;charset=UTF-8")
    @ResponseBody
    public Object batchUpload(@RequestParam String orderId, @RequestParam("file") MultipartFile file, HttpServletResponse response) {
        response.setHeader("Cache-Control", "no-cache");
        response.setHeader("X-Frame-Options", "SAMEORIGIN");
        response.setHeader("Access-Control-Allow-Origin", "*");
        
        String filePath = fileUploadService.upload(file);
        Map result = new HashedMap();
        if (filePath == null) {
            result.put("status", 0);
        } else {
            result.put("status", 1);
            result.put("filePath", filePath);
        }
        return JSON.toJSONString(result);
    }

What is the exact difference between content-type: text/json and application/json? 

application/json: Official MIME type for json

text/x-json: Experimental(unofficial) MIME type for json before application/json got officially registered