idea httpclient 用法

没时间详细整理了，简单先记录一下

IDEA HttpClient 文件上传
https://blog.csdn.net/qq_38887189/article/details/78305814

文件上传
https://www.cnblogs.com/fugitive/p/13606288.html

设置变量
https://www.jianshu.com/p/c6d2413784de