This is my personal collection of tips for Oracle XE.
How to change the default HTTP listener port
The default port of the Oracle Express HTTP Port Listener is 8080. You can change this running the following command with SQLPlus or the Web interface http://localhost:8080/apex logging as SYS:
begin dbms_xdb.sethttpport('8180'); end;
You can also run these commands with the Web Administration Console: Open the Database Home Page in the Start Menu and log as the SYS user. Use the password selected during the installation.
To get the number of the port currently in use, you should run:
select dbms_xdb.gethttpport as "HTTP-Port" from dual;