How can I add Header and footer in pdf using iText

问题:

I am trying to add Header and footer in my pdf(iText). For this I have created one servlet and I also created one class HeaderandFooter that extends PdfPageEventHelper.

public class HeaderAndFooter extends PdfPageEventHelper {
    public HeaderAndFooter(String name) {
        super();
    }

    @Override
    public void onEndPage(PdfWriter writer, Document document) {
        super.onEndPage(writer, document);
        //code

    }
    @Override
    public void onStartPage(PdfWriter writer, Document document) {
        super.onStartPage(writer, document);
                //code

    }
}

But I dont know what should I write in a method so that It will display heading any text and in footer page no.

回答1:

Have a look at this example taken from the iText in Action book.

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);
    }
}