HTTP Request Content-Type：application/x-www-form-urlencoded、multipart/form-data、application/json

http 请求

http 请求由三部分组成，分别是：请求行、消息报头、请求正文。

POST /api/sample/form/post1 HTTP/ (CRLF)
Accept:*/*(CRLF)
...
HOST:192.168.0.55:8085 (CRLF)
Content-Length:22 (CRLF)
Connection:Keep-Alive (CRLF)
Cache-Control:no-cache (CRLF)
(CRLF)         //该CRLF表示消息报头已经结束，在此之前为消息报头
user=jeffrey&pwd=1234  //此行以下为提交的数据

curl 的表述形式：

curl -X POST "http://192.168.0.55:8085/api/sample/form/post1" 
     -H "Content-Type: application/x-www-form-urlencoded" -d "pwd=123&user=jeffrey"

HTTP 请求的 Content-Type

HTTP 请求的 Content-Type 作用于请求正文部分。Content-Type 的默认值为 application/x-www-form-urlencoded。

HTTP 请求的 Content-Type 取值：

• application/x-www-form-urlencoded
• multipart/form-data
• application/json
• …

application/x-www-form-urlencoded

curl -X POST "http://192.168.0.55:8085/api/sample/form/post1" 
     -H "Content-Type: application/x-www-form-urlencoded" -d "pwd=123&user=jeffrey"

multipart/form-data

curl 的表述形式：

curl -X POST "http://192.168.0.55:8085/api/common/upload/file" -H "accept: */*" 
     -H "Content-Type: multipart/form-data" -F "file=@2.jpg;type=image/jpeg"

application/json

curl -X POST "http://192.168.0.55:8085/api/sample/form/post3" -H "accept: application/json" 
     -H "Content-Type: application/json" -d "{ \"mobile\": \"13012341234\",  \"password\": \"123456\"}"

参考

区分 application/x-www-form-urlencoded、multipart/form-data

https://www.cnblogs.com/coce/p/9720285.html
https://www.cnblogs.com/wuyun-blog/p/7724495.html
https://blog.csdn.net/zsensei/article/details/80043764
https://blog.csdn.net/Andrewniu/article/details/81533905
https://blog.csdn.net/Andy2019/article/details/100112550

ajax 的 processData 参数

https://blog.csdn.net/u012235103/article/details/89552453
https://blog.csdn.net/weixin_34191845/article/details/88012221

https://www.cnblogs.com/tu-0718/p/8370925.html
https://www.cnblogs.com/yangguoe/p/8986108.html
https://www.cnblogs.com/mahuan2/p/6008832.html
https://stackoverflow.com/questions/12893566/passing-multiple-variables-in-requestbody-to-a-spring-mvc-controller-using-ajax
https://github.com/chujianyun/Spring-MultiRequestBody
https://blog.csdn.net/w605283073/article/details/82119284
https://stackoverflow.com/questions/37922973/spring-mvc-file-upload-unable-to-process-parts-as-no-multi-part-configuration
https://blog.csdn.net/qq_34608620/article/details/80635139
https://blog.csdn.net/qq_36798969/article/details/104692248