String fileName = "xmp_metadata_automatic.pdf";
// step 1
Document document = new Document();
// step 2
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(OUT_FOLDER + fileName));
document.addTitle("Hello World example");
document.addSubject("This example shows how to add metadata & XMP");
document.addKeywords("Metadata, iText, step 3");
document.addCreator("My program using 'iText'");
document.addAuthor("Bruno Lowagie & Paulo Soares");
writer.createXmpMetadata();