You can use a custom PdfpageEvent to add text or a table or whatever to the footer.
Here is some code that adds a 4 column table to the footer (sorry it's in C#):
public override void OnEndPage(PdfWriter writer, iTextSharp.text.Document document)
{
base.OnEndPage(writer, document);
PdfContentByte cb = writer.DirectContent;
var footerTable = new PdfPTable(4);
var columnWidth = (document.Right - document.LeftMargin) / 4;
footerTable.SetTotalWidth(new float[] { columnWidth, columnWidth, columnWidth, columnWidth });
var cell1 = new PdfPCell();
cell1.AddElement(new Paragraph("Date:"));
cell1.AddElement(new Paragraph(DateTime.Now.ToShortDateString()));
footerTable.AddCell(cell1);
var cell2 = new PdfPCell();
cell2.AddElement(new Paragraph("Data:"));
cell2.AddElement(new Paragraph("123456789"));
footerTable.AddCell(cell2);
var cell3 = new PdfPCell();
cell3.AddElement(new Paragraph("Date:"));
cell3.AddElement(new Paragraph(DateTime.Now.ToShortDateString()));
footerTable.AddCell(cell3);
var cell4 = new PdfPCell();
cell4.AddElement(new Paragraph("Page:"));
cell4.AddElement(new Paragraph(document.PageNumber.ToString()));
footerTable.AddCell(cell4);
footerTable.WriteSelectedRows(0, -1, document.LeftMargin, cell4.Height + 50, cb);
}
and this is the code that would call the above code:
var pdfWriter = PdfWriter.GetInstance(pdf, new FileStream(fileName, FileMode.Create));
pdfWriter.PageEvent = new CustomPdfPageEvent();