To use the OPI interface, the XML parser must be installed in the database.
The XML parser has been installed properly if the following SQL statement:
SELECT SUBSTR(dbms_java.longname(object_name),1,30) AS class, status
FROM all_objects
WHERE object_type = 'JAVA CLASS'
AND object_name = dbms_java.shortname('oracle/xml/parser/v2/DOMParser');
returns the following result:
CLASS STATUS
--------------------------------- ---------
oracle/xml/parser/v2/DOMParser VALID