Why is content missing in my table?

I am adding image cells based on an imagelist that may not contain 6 or 12 or 18 images. The number of images can be 1 or 7 or anything.

try {
    Document document = new Document(PageSize.A4.rotate());
    PdfWriter writer = PdfWriter.getInstance(document,
        new FileOutputStream(new File(sourcePath, AppText.FILE_NAME)));
    PdfPTable table = new PdfPTable(6);
    document.open();
    Paragraph paragraph = new Paragraph("Diary Report");
    paragraph.setSpacingAfter(50);
    paragraph.setSpacingBefore(50);
    document.add(paragraph);
    table.setHorizontalAlignment(Element.ALIGN_LEFT);
    for (String imageFile : imageFiles) {
        Image image = Image.getInstance(new File(imageFile).getAbsolutePath());
        PdfPCell cell = new PdfPCell(image, true);
        cell.setPadding(10);
        table.addCell(cell);
    }
    document.add(table);
    document.close();
    return "successful";
} catch (DocumentException | IOException e) {
    e.printStackTrace();
}

The way of creating tables in iText 7 differs from the previous version. You should replace PdfPTable and PdfPCell instances with Table and Cell respectively. Look at the IncompleteTable example. With a few changes your code will look like this:

public void createPdf(String imgSrc, String dest) throws IOException {
    PdfDocument pdfDoc = new PdfDocument(new PdfWriter(dest));
    Document doc = new Document(pdfDoc);
    Image img = new Image(ImageDataFactory.create(imgSrc)).setAutoScale(true);
    Table table = new Table(6, true);
    for (int i = 1; i 

As you see, we create a table with 6 columns, setting the second parameter in the constructor as true. It means that the table, being added to the document, will not be complete. In the first loop we add a header with a Paragraph instances. Then add the table to the document. In the second loop we add new cells with images, but in such a way, that the last (third) row will have only 2 cells. Executing complete() method we tell iText to render all cells.

The result looks like this:

Screenshot

Click this link if you want to see how to answer this question in iText 5.