restful,ca,httpclient,https

http://www.ruanyifeng.com/blog/2011/09/restful.html

http://openmind.iteye.com/blog/1691716

http://www.zhyea.com/2016/09/11/httpclient-multi-thread.html

https://my.oschina.net/ydsakyclguozi/blog/612886

http://www.cnblogs.com/ITtangtang/p/3968093.html