Align Paragraph at the center of the page

Use Paragraph#setAlignment(int) :

Paragraph preface = new Paragraph(); 
preface.setAlignment(Element.ALIGN_CENTER);

See the ALIGN_* constants in the Element interface for more possible values.

Not sure if this is an old version, but for PdfWriter these methods weren't there. Instead I used:

Paragraph p = new Paragraph("This too shall pass");
p.Alignment = Element.ALIGN_CENTER;

 public static final String DEST = "results/tables/centered_text.pdf";


public static void main(String[] args) throws IOException, DocumentException {
    File file = new File(DEST);
    file.getParentFile().mkdirs();
    new CenteredTextInCell().createPdf(DEST);
}

public void createPdf(String dest) throws IOException, DocumentException {
    Document document = new Document();
    PdfWriter.getInstance(document, new FileOutputStream(dest));
    document.open();
    Font font = new Font(FontFamily.HELVETICA, 12, Font.BOLD);
    Paragraph para = new Paragraph("Test", font);
    para.setLeading(0, 1);
    PdfPTable table = new PdfPTable(1);
    table.setWidthPercentage(100);
    PdfPCell cell = new PdfPCell();
    cell.setMinimumHeight(50);
    cell.setVerticalAlignment(Element.ALIGN_MIDDLE);
    cell.addElement(para);
    table.addCell(cell);
    document.add(table);
    document.close();
}