看看这个取自iText in Action的例子。
class TableHeader extends PdfPageEventHelper {
/** The header text. */
String header;
/** The template with the total number of pages. */
PdfTemplate total;
/**
* Allows us to change the content of the header.
* @param header The new header String
*/
public void setHeader(String header) {
this.header = header;
}
/**
* Creates the PdfTemplate that will hold the total number of pages.
* @see com.itextpdf.text.pdf.PdfPageEventHelper#onOpenDocument(
* com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
*/
public void onOpenDocument(PdfWriter writer, Document document) {
total = writer.getDirectContent().createTemplate(30, 16);
}
/**
* Adds a header to every page
* @see com.itextpdf.text.pdf.PdfPageEventHelper#onEndPage(
* com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
*/
public void onEndPage(PdfWriter writer, Document document) {
PdfPTable table = new PdfPTable(3);
try {
table.setWidths(new int[]{24, 24, 2});
table.setTotalWidth(527);
table.setLockedWidth(true);
table.getDefaultCell().setFixedHeight(20);
table.getDefaultCell().setBorder(Rectangle.BOTTOM);
table.addCell(header);
table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_RIGHT);
table.addCell(String.format("Page %d of", writer.getPageNumber()));
PdfPCell cell = new PdfPCell(Image.getInstance(total));
cell.setBorder(Rectangle.BOTTOM);
table.addCell(cell);
table.writeSelectedRows(0, -1, 34, 803, writer.getDirectContent());
}
catch(DocumentException de) {
throw new ExceptionConverter(de);
}
}
/**
* Fills out the total number of pages before the document is closed.
* @see com.itextpdf.text.pdf.PdfPageEventHelper#onCloseDocument(
* com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
*/
public void onCloseDocument(PdfWriter writer, Document document) {
ColumnText.showTextAligned(total, Element.ALIGN_LEFT,
new Phrase(String.valueOf(writer.getPageNumber() - 1)),
2, 2, 0);
}
}