How to test connection to server SSL port via proxy using Apache HttpClient 4.3.4?

Question

I'm trying to validate an SSL connection to an http server through a proxy server. In my case, I have 4 pieces of information which are all supplied by the user, and which I'd like to validate explicitly: target host, target port, proxy host, proxy port. I'd prefer to NOT make an actual HTTP request in order to do this validation, since that requires 2 more pieces of information: a request method, and a path (ie. "GET /"). I'd really like to be able to use the HttpClient library because it supports NTLM proxy auth.

I suppose what I want is to get the response of a CONNECT request sent to the proxy server, as all it requires are the 4 pieces of information I have (plus any proxy creds). However this seems to be an implicit request, the result of which is not available to the library client (unless it returns a 407 status code). Is there some way to trigger the CONNECT request explicitly?

Answer 1

You can use ProxyClient shipped with Apache HttpClient. It does precisely that.