how to change oracle port:8080 to 9090

By default Apache tomcat server runs on the port 8080.
Oracle server also runs on the same port 8080.
It is impossible to  run both the servers on the same port 8080 and it leads to the port conflicts error.
To avoid such port conflicts we should change any one of port from 8080 to 9090 or 8181.

Steps to change oracle port 8080 to 9090

SQL>conn system/tiger
SQL> -- set http port
SQL> begin
 2    dbms_xdb.sethttpport('9090');
 3  end;
 4  /
Sql>set serveroutput on