Oracle Database Discussions

This error appears when I configure the BPM suite. However, I think the problem is about the Oracle 11g for linux. Therefore, I post this thread in this forum.

I login as oracle and install BPM Enterprise J2EE/weblogic 10.3.1 for linux , weblogic server 10.3 for Linux , and Oracle database 11g for Linux on RedHad linux Enterprise 5.
I login as oracle and startup Oracle database.
However, when I configure the BPM Enterprise, it is failed at about 6-7%. It shows error messages as follow

[BEA][Oracle JDBC Driver] Error establishing socket to host and port: localhost.localdomain:1521. Reason: Connection refused

URL of DB: jdbc:bea:oracle://localhost.localdomain:1521;SID=ORCL

------------------------------/u01/app/oracle/product/11.1.0/db_1/network/admin/tnsnames.ora--------------------------------
ORCL=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521))
(CONNECT_DATA=
(SERVER=DEDICATED)
(SERVER_NAME=orcl)
)
)

----------------------------sqlnet.ora-------------------------------------------
NAMES.DIRECTORY_PATH=(TNSNAMES, EZCONNECT)

---------------------------listener.ora-------------------------------------------
LISTENER =
(DESCRIPTION_LIST=
(DESCRIPTION=
(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521))
(ADDRESS=(PROTOCOL=TPC)(HOST=localhost.localdomain)(PORT=1521))
)
)


I am new in linux