OSS Web直传 文件上传成功后， 不执行回调函数？

在后台管理界面可以看到文件上传成功了，但回调没执行，我在服务端打了断点，确定未执行。设置了callback 且如下文所示：
Request URL:http://classcard.oss-cn-zhangjiakou.aliyuncs.com/
Request Method:POST
Status Code:200 OK
Remote Address:47.92.17.84:80
Referrer Policy:no-referrer-when-downgrade
Response Headers
view source
Access-Control-Allow-Methods:POST
Access-Control-Allow-Origin:*
Access-Control-Max-Age:600
Connection:keep-alive
Content-Length:0
Content-MD5:l61HWFEkfYwmVtgxIiLNrQ==
Date:Tue, 15 Aug 2017 06:45:49 GMT
ETag:"97AD475851247D8C2656D8312222CDAD"
Server:AliyunOSS
x-oss-hash-crc64ecma:13691150632828638184
x-oss-request-id:5992989DBCC5818299796195
x-oss-server-time:80
Request Headers
view source
Accept:/
Accept-Encoding:gzip, deflate
Accept-Language:zh-CN,zh;q=0.8,en-US;q=0.6,en;q=0.4
Connection:keep-alive
Content-Length:3332
Content-Type:multipart/form-data; boundary=----WebKitFormBoundaryuTYT7au67ef8lf18
Host:classcard.oss-cn-zhangjiakou.aliyuncs.com
Origin:http://localhost:18080
Referer:http://localhost:18080/demo_0.0.1-SNAPSHOT_20170720085032/oss/getPolicy
User-Agent:Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36
Request Payload
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="name"

hellenic.lang
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="key"

user-dirhellenic.lang
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="policy"

eyJleHBpcmF0aW9uIjoiMjAxNy0wOC0xNVQwNjo0NjoxOS42NTVaIiwiY29uZGl0aW9ucyI6W1siY29udGVudC1sZW5ndGgtcmFuZ2UiLDAsMTA0ODU3NjAwMF0sWyJzdGFydHMtd2l0aCIsIiRrZXkiLCJ1c2VyLWRpciJdXX0=
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="OSSAccessKeyId"

LTAIAitjQf0XuC8O
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="success_action_status"

200
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="signature"

Cc25RuPSsU70hCxItrGpmhODULE=
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="callback"

"eyJjYWxsYmFja1VybCI6Imh0dHA6Ly80Ny45Mi41Mi4xNDE6MTAxNTgiLCJjYWxsYmFja0hvc3QiOiJodHRwOi8vNDcuOTIuNTIuMTQxIiwiY2FsbGJhY2tCb2R5IjoiZmlsZW5hbWU9JChmaWxlbmFtZSkiLCJjYWxsYmFja0JvZHlUeXBlIjoiYXBwbGljYXRpb24veC13d3ctZm9ybS11cmxlbmNvZGVkIn0="
------WebKitFormBoundaryuTYT7au67ef8lf18
Content-Disposition: form-data; name="file"; filename="hellenic.lang"
Content-Type: application/octet-stream

------WebKitFormBoundaryuTYT7au67ef8lf18--