Without using tor2web is there a way for my Java program to connect to a hidden service .onion and retrieve data, for example search and then download a file?
I want the easiest solution possible, so it does not just have to be a programming solution.
You can use any networking library for Java that speaks SOCKS5, then you can make connections via localhost:9050 to any location-hidden services (or clearnet services) via Tor.
If you are on a linux machine (possibly also other OSes), you can try the torify tool which comes with tor. It receives a command line as an argument and sends the TCP connections of that program through the Tor process running on your machine.
PS: I use it myself to connect to a sshd running on my .onion from outside.
