Is there a way to set the Author property to a PDF document by setting a parameter when calling Jasper from Java.

This is how I generate a Jasper report from Java.
JasperPrint jasperPrint;
String outFile = "39285923953222.pdf";
HashMap hm = new HashMap();
hm.put("ID",id);
hm.put("FOOTER",Constants.FOOTER); // Set somehow a string for the author name
Session session = this.sessionFactory.openSession();
Connection con = session.connection();
jasperPrint = JasperFillManager.fillReport(jasperPath + "myReport.jasper", hm, con);
JasperExportManager.exportReportToPdfFile(jasperPrint, outPath + outFile);
Look at static field METADATA_AUTHOR in JRPdfExporterParameter.
Use JRPdfExporter instead of
JasperExportManager.Example :