you can use JRBeanArrayDataSource or JRBeanCollectionDataSource
that contain POJO,

for example:
JRBeanCollectionDataSource dataSource;
List reportData = ...;
dataSource = new JRBeanCollectionDataSource(reportData);

by passing this datasource to report,
Jasper evaluate POJO properties with report  fields based on name,
and put proper value (from pojo) to proper field on report.