BIServlet
is a simple servlet that demonstrates how a BI application
can set up a connection to OLAP (the source of the business data for
the application) and to the BI Beans Catalog (where object definitions, such
as crosstabs and graphs, are saved).
The first page displayed by the servlet prompts a user for security credentials. It then makes the two connections described above. The second page reports the status of the connections. The user can disconnect the connections described above on the second page of the servlet.
This sample is used by the other samples that require the connections.
The connect
method in the sample shows how connections to the
Oracle OLAP Services and the BI Beans Catalog are created. The following
section provides a walkthrough and explanations of the code fragments.
Before it sets up the connections,
an application must first create a new user session. This is accomplished
by creating a new BISession
object. A BISession
can take the name of a BI Configuration file as an argument. A BI Configuration
file is an XML file that contains the definition of the connections.
m_session
= new BISession(m_configFile);
In addition, an application must specify the name of the application user.
m_session.setBIUser(new
BIUser(userName));
Note that this information could also be specified within the BI Configuration file.
After a session has been created, an application can retrieve the MetadataManager
that is already associated with the specified connections through the ManagerFactory
(since the connection definitions are already defined in the BI Configuration
file).
m_metadataManager
= (MetadataManager)m_biSession.getManagerFactory().lookupManager(ManagerFactory.METADATA_MANAGER,
null, true);
The application can use the ManagerFactory
to retrieve the QueryManager
.
m_queryManager = (QueryManager)m_biSession.getManagerFactory().lookupManager(ManagerFactory.QUERY_MANAGER,
null, true);
The disconnect
method in the sample shows how to disconnect from
OLAP and from the BI Beans Catalog.
All that the application has to do is to disconnect the current user session
by calling the disconnect
method on the BISession
object.
m_session.disconnect();
For applications using thin beans, the MetadataManager needs to create the
ThinCrosstab
, ThinGraph
and ThinTable
when it loads the Crosstab, Graph and Table objects from the BI Beans Catalog.
The ObjectFactory
instance of the MetadataManager is initialized
to use the thin classes when loading the objects from the BI Beans Catalog.
ObjectFactory objectFactory = m_metadataManager.getObjectFactory(false);
if(objectFactory != null) {
objectFactory.setObjectInstanceClassName(PersistableConstants.CROSSTAB,
"oracle.dss.thin.beans.crosstab.ThinCrosstab" );
objectFactory.setObjectInstanceClassName(PersistableConstants.GRAPH,
"oracle.dss.thin.beans.graph.ThinGraph" );
objectFactory.setObjectInstanceClassName(PersistableConstants.TABLE,
"oracle.dss.thin.beans.table.ThinTable" );
}
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