Unable to connect APEX after bouncing the DB

Hi,

We have installed apex 4.1 on 11G Enterprise Edition and its works fine, after bouncing the Database now we are unable to access the APEX via http://localhost:8080/apex..

i had used the following query 

SELECT STATUS FROM DBA_REGISTRY

WHERE COMP_ID = 'APEX';

it returns "VALID"  

SELECT dbms_xdb.gethttpport AS http_port FROM dual;

it returns "8080"  

Could anyone tell what are the steps to be followed, Kindly suggest a solution as soon as possible

Regards,

Karthik