httpclient/httpcore是apache下面的项目:中文文档下载参考 5
参考:
1、https://www.crifan.com/java_http_related_lib_httpclient_httpcore/
2、https://www.ibm.com/developerworks/cn/java/j-lo-okhttp/index.html
3、https://www.jianshu.com/p/b2057bcf512d
4、https://www.jianshu.com/p/e955b01e2e16
5、https://code.google.com/archive/p/translation/downloads