To create a new empty data source with more records:
|1.||Double-click One Empty Record in the Repository Explorer. The Data Adapter Wizard appears with Empty rows.|
Data Adapter Wizard > Empty Record
|2.||Set the number of empty records you need. Remember, whatever field you add to the report, its value is set to null. Since this data adapter doesn’t care about field names or types, this is a perfect way to test any report (keeping in mind that the fields are always set to null).|
The empty record data adapter in Jaspersoft Studio uses the special JasperReports data source JREmptyDataSource. This data source returns true to the next method for the record number (by default only one), and always returns null to every call of the getFieldValue method. It's like having records without fields, that is, an empty data source.
The two constructors of this class are:
public JREmptyDataSource(int count)
The first constructor indicates how many records to return, and the second sets the number of records to one.