jasperreport JRDataSource

While working on report for some client, guys and me, we've succeeded to define(Java), populate(from Hibernate v3.x) and 'feed' custom data source (in pseudo raw SQL something like:

select t1.c1,t2.c2,t3.c3 ... join-joi开发者_开发技巧n-join ...

)

to

JasperFillManager(API v3.6.7):
ds = JasperFillManager.fillReport(fillReport(java.lang.String sourceFileName,      
    java.util.Map params, JRDataSource myCustomDataSource);

1. Now the BIG issue comes when we trying with iReport (v4.0.2) to populate this custom data source into report(either sub-report). We've tried to pass it as parameter, as single data source to fillReport() - nAdA. Help please.
2. Now at all, conceptualy or by example, how to pass number if different custom data sources into sub-reports. Example could be very helpful.

Appreciate the help, --vs