Variable null if report is paginated

[PabloRO]

Hi, im new to Jasper and im trying to learn at the moment cause of my job.

Im developing a report which has a table filled with data from a secondary dataset. 

I need to get the first and last register from the table in a variable and i encountered 2 problems:

If its not paginated, i only get the value of the last register and I dont realise how to get the first value.

If the report generates page 2, the table stay at the first page and the section where i print the variables at second page. In this case variables are null.

I cannot share code for professional reasons, but i hope you can still help me.