I hope someone can put some clarification on this problem that I'm having.
I am using Apache HTTPClient 4.2 library and I use proxies to connect to internet.
For normal proxies I don't have any problem and it goes through the proxy but I'm not sure how this works when the proxy requires an authentication.

Can someone tell the implementation required to authenticate the proxy via username and pass(which I have) and then connect via proxy to the internet?

In addition, is it possible to connect to multiple proxies? for example,assume that I want to connect to one proxy and then use that proxy to connect to another which then will connect to internet, is this achievable in Java using httpclient?

Any link containing guides,tutorial are welcome too

Thank you