Once we need to connect to a site that uses two way SSL but it was not possible to implement that to the current client, so we needed a proxy that can do it for us.

After a short googling, I found two good examples:

Rest Template using http proxy http://stackoverflow.com/questions/3687670/using-resttemplate-how-to-send-the-request-to-a-proxy-first-so-i-can-use-my-jun TWO WAY SSL example https://github.com/viniciusccarvalho/boot-two-way-ssl-example

and here it is, end of story :)