itext Page events (iText 5) versus Event handlers and Renderers (iText 7) Text2PdfPageEvents.java (iText 5)

Example

Suppose that we have the following text file: jekyll_hyde.txt

How do we convert it to a PDF that looks like this:

Note the blue border that is added to the titles, and the page number at the bottom of each page. In iText 5, these elements are added using page events:

class MyPageEvents extends PdfPageEventHelper {

    protected float startpos = -1;
    protected boolean title = true;

    public void setTitle(boolean title) {
        this.title = title;
    }

    @Override
    public void onEndPage(PdfWriter writer, Document document) {
        Rectangle pagesize = document.getPageSize();
        ColumnText.showTextAligned(
            writer.getDirectContent(),
            Element.ALIGN_CENTER,
            new Phrase(String.valueOf(writer.getPageNumber())),
            (pagesize.getLeft() + pagesize.getRight()) / 2,
            pagesize.getBottom() + 15,
            0);
        if (startpos != -1)
            onParagraphEnd(writer, document,
                pagesize.getBottom(document.bottomMargin()));
        startpos = pagesize.getTop(document.topMargin());
    }

    @Override
    public void onParagraph(PdfWriter writer, Document document,
        float paragraphPosition) {
        startpos = paragraphPosition;
    }

    @Override
    public void onParagraphEnd(PdfWriter writer, Document document,
        float paragraphPosition) {
        if (!title) return;
        PdfContentByte canvas = writer.getDirectContentUnder();
        Rectangle pagesize = document.getPageSize();
        canvas.saveState();
        canvas.setColorStroke(BaseColor.BLUE);
        canvas.rectangle(
            pagesize.getLeft(document.leftMargin()),
            paragraphPosition - 3,
            pagesize.getWidth() - document.leftMargin() - document.rightMargin(),
            startpos - paragraphPosition);
        canvas.stroke();
        canvas.restoreState();
    }
}

We can reuse the code to convert a text file to a PDF from the Text2Pdf.java (iText 5) example, and introduce the page event to the PdfWriter:

public void createPdf(String dest)
throws DocumentException, IOException {
    Document document = new Document();
    PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest));
    MyPageEvents events = new MyPageEvents();
    writer.setPageEvent(events);
    document.open();
    BufferedReader br = new BufferedReader(new FileReader(TEXT));
    String line;
    Paragraph p;
    Font normal = new Font(FontFamily.TIMES_ROMAN, 12);
    Font bold = new Font(FontFamily.TIMES_ROMAN, 12, Font.BOLD);
    boolean title = true;
    while ((line = br.readLine()) != null) {
        p = new Paragraph(line, title ? bold : normal);
        p.setAlignment(Element.ALIGN_JUSTIFIED);
        events.setTitle(title);
        document.add(p);
        title = line.isEmpty();
    }
    document.close();
}

Source: developers.itextpdf.com