SQL Developer The Network Adapter could not establish the connection

Question

I've downloaded the latest SQL Developer and Oracle Databse XE, and when i try to connect to it, i get this error:

Status : Failure -Test failed: IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=kh7QxUIUTHGSeYuTcGRyDA==)

I tried restarting the service, and my listener is in fact listening.

EDIT: Additionally, when i try to connect to the database, using SQL Plus, i get:

ORA-12541: TNS:no listener

SOLVED: Pretty much a newbie thing, but what i had to do, was to use a hostname that resides under hostname in cmd, instead of localhost.