Line Wrap for excel cells

DO:
In report manager,
exporter.setParameter(JExcelApiExporterParameter.IS_COLLAPSE_ROW_SPAN, Boolean.TRUE);

In xml,
textField isStretchWithOverflow="true" // on long data input cells
reportElement stretchType="RelativeToTallestObject"

API: http://jasperreports.sourceforge.net/api/net/sf/jasperreports/engine/export/JRXlsAbstractExporterParameter.html