JasperReports: Passing in a list of lists as a datasource

Question

I need to populate a few subreports with lists of different objects. Basically lets say i have the following:
Subreport on used Vehicles
Subreport on new Vehicles

I create a vehicle bean class with variables as strings and create getter and setter methods for the same. Then in my datasource I pass in a List<List<String>> as detailRows. detailRows contains a list for new vehicles and a list for used vehicles. So lets say, i pass detailRows in the data source.
Question is how do i pass these two lists to the two sub-reports? Can i use new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F{newVehiclesList}) as a datasource for sub report 1 and new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F{usedVehiclesList}) as datasource for sub report 2?
Is there anything else that needs to be done apart from what i mentioned? Do i need to create and pass any variables? Is the appropriate use of the list of lists as i have listed above or is it $F{detailRows}.get(0)?

I created a field detailRows in the main report as type list. I then pass the following to the subreport data source expression, new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F{detailRows} Is there any way i can pass the newVehiclesList from detailRows to the sub-report?

Thanks!

Answer 1

Ok, then you need create two fields with the Field Class as java.util.List, one for each list (newVehiclesList and usedVehiclesList).

Put your two SubReports wherever you want and click on each one doing the following steps:

Change the "Connection type" to "Use a datasource expression" then change the "Data Source Expression" to new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F{yourField})

Done.

ps: In order to use the fields inside your newVehiclesList and usedVehiclesList you have to create them inside of their own subReports.