Bug 416703 Mongodb : Display correctly the Number data type
data/org.eclipse.birt.data.oda.mongodb/src/org/eclipse/birt/data/oda/mongodb/internal/impl/MDbMetaData.java
public List<String> getCollectionsList( boolean excludeSystemCollections )
    {
        Set<String> collectionNames;
        try
        {
            collectionNames = m_connectedDB.getCollectionNames();
        }
        catch( MongoException ex )
        {
            
            DriverUtil.getLogger().log( Level.INFO, "Ignoring error to get collection names from database.", ex ); 
            return Collections.emptyList();
        }
        if( excludeSystemCollections )
        {
            List<String> filteredNames = new ArrayList<String>(collectionNames.size());
            for( String collectionName : collectionNames )
            {
                if( ! collectionName.startsWith( SYSTEM_NAMESPACE_PREFIX ) )
                    filteredNames.add( collectionName );
            }
            return filteredNames;
        }
        
        return new ArrayList<String>( collectionNames );
    }
    public DBCollection getCollection( String collectionName )
    {
        if( ! m_connectedDB.collectionExists( collectionName ) )
            return null;