Minecraft java.net.connectionexception: connection refused, no further information?

Minecraft java.net.connectionexception: connection refused, no further information?

Added (1). When i try to join my friend's server, it says precisely that ^^^. I'm using a windows7 32 bit pc. Any help?

Here's a few possible causes:
-your friend didn't give you correct IP address (I've seen people giving out their loop back address which only works for them)
-your friend didn't port forward the correct port
-your friend didn't whitelist your minecraft username

Why is not connecting to other server?