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iText performance: Generate or populate pdf forms?

I want to write some text in a PDF file.
Approach 1: Using AcroForms.
To me, this the simplest approach. But we have some performance doubts. Using this approach, I'll be embedding a PDF template that contains in my resources folder and populating already existing fields that I've already created in Acrobat like so:
PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(DEST));
PdfAcroForm form = PdfAcroForm.getAcroForm(pdfDoc, true);
form.setGenerateAppearance(true);
form.getField("name")
.setVisibility(PdfFormField.VISIBLE)
.setReadOnly(true)
.setValue("Hamza Belmellouki");
// other fields being set
Approach 2: Generate the PDF from Scratch.
In this approach, I write the whole content to the file(Static content as well as dynamic one) and generate it.
In terms of performance, I am wondering which approach should we go with?

Cannot read generated text of pdf file in Java

I am trying to read the text in Java and it isn't doing well.
Here is my code
PDFTextStripper pdfStripper = null;
PDDocument pdDoc = null;
COSDocument cosDoc = null;
File pdfFile = new File("1.pdf");
PDFParser parser = new PDFParser(new RandomAccessFile(pdfFile,"rw"));
parser.parse();
cosDoc = parser.getDocument();
pdfStripper = new PDFTextStripper();
pdDoc = new PDDocument(cosDoc);
pdfStripper.setStartPage(1);
pdfStripper.setEndPage(5);
String parsedText = pdfStripper.getText(pdDoc);
System.out.println(parsedText);
But the result like this
Please wait...
If this message is not eventually replaced by the proper contents of the document, your PDF
viewer may not be able to display this type of document.
You can upgrade to the latest version of Adobe Reader for Windows®, Mac, or Linux® by
visiting http://www.adobe.com/go/reader_download.
For more assistance with Adobe Reader visit http://www.adobe.com/go/acrreader.
Windows is either a registered trademark or a trademark of Microsoft Corporation in the United States and/or other countries. Mac is a trademark
of Apple Inc., registered in the United States and other countries. Linux is the registered trademark of Linus Torvalds in the U.S. and other
countries.
I found this error occurred because of xfa pdf document.
But I don't know about xfa format of my pdf document.
So please Let me know how can I know about xfa format.
Someone help me please.
Thank you!

To sum up what has been said or hinted at in the comments...
The text quoted by the OP,
Please wait...
If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document.
...
is the content of the single PDF page Adobe software commonly puts into PDFs with a pure XFA form.
XFA forms constitute an alternative way to describe forms in PDFs. In contrast to the AcroForm way, XFA forms only use PDFs as an envelope carrying a XML stream describing properties, behavior, and values of the form in a way unrelated to any other PDF structure.
Thus, many PDF processors offer a rudimentary support for XFA forms only (or none at all), the main exception being (obviously) Adobe products.
As a result XFA has been marked deprecated in the current PDF specification ISO 32000-2.
In case of PDFBox the XFA support is restricted to the feature of retrieval of the XFA XML data. Text extraction using the PdfTextStripper and related classes only operates on the regular PDF content and, therefore, only retrieves the text reported by the OP.
To access the content of XFA forms, you can retrieve the XFA resource using PDAcroForm.getXFA().

How to export data set using pdf template with itext?

In my project, some data sets are needed to be exported in PDF format.
I learned that iText is helpful, and PdfpTable can do the work, but it needs much code to deal with styles. While using PDF template can save time and code for adjusting style, but I can only set certain fields left in the template.
Can you give me some suggestions to show the data sets using commands like foreach? Thanks in advance!
Here are my code using pdfpTable, which has done the work, but the code is a little ugly:
PdfPTable pdfTable = createNewPDFTable();
for (int i = 0; i < dataSet.size(); i++) {
MetaObject metaObject = SystemMetaObject.forObject(dataSet.get(i));
for (String field : fields) {
Phrase phrase = new Phrase(String.valueOf(metaObject.getValue(field) != null ? metaObject.getValue(field) : "")
, PDFUtil.createChineseSong(DEFAULT_CELL_FONT_SIZE));
PdfPCell fieldCell = new PdfPCell(phrase);
fieldCell.setBorder(Rectangle.NO_BORDER);
fieldCell.setFixedHeight(DEFAULT_COLUMN_HEIGHT);
fieldCell.setHorizontalAlignment(Element.ALIGN_CENTER);
fieldCell.setVerticalAlignment(Element.ALIGN_MIDDLE);
pdfTable.addCell(fieldCell);
}
}
Here are some code using pdfp template,which is copied from itext examples, the work is unfinished yet because i haven't find a proper way to show the data set.
PdfReader reader = new PdfReader(src);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
AcroFields form = stamper.getAcroFields();
form.setField("text_1", "Bruno Lowagie");
form.setFieldProperty("text_1", "setfflags", PdfFormField.FF_READ_ONLY, null);

There is an inconsistency in your question. You write: PdfpTable can do the work, but it needs much code to deal with styles. However, in your first code snippet, you don't really create your PDFs the way one would expect. Instead of producing a high volume of finished PDFs, you create use PdfPTable to create a template. I assume you then use that template to create a high volume of finished PDFs.
If you want to use a template and populate it afterwards, you shouldn't create your form using iText. Create it manually, for instance using Open Office or Libre Office. See for instance the example in chapter 6 of my book (section 6.3.5). Create the template with a tool that has a GUI, then fill out that template many times using iText.
This approach has some down-sides: all the content has to fit the fields you define. All fields have a fixed position on a fixed page.
If "applying styles through code" is a problem, you may want to follow the approach described in the ZUGFeRD book. In that book, we create HTML first: Creating HTML invoices.
Once you have the HTML, then convert the HTML to PDF, and use CSS to apply styles: Creating PDF invoices.
This is how we create a ZUGFeRDDocument:
ZugferdDocument pdfDocument = new ZugferdDocument(
new PdfWriter(fos), ZugferdConformanceLevel.ZUGFeRDComfort,
new PdfOutputIntent("Custom", "", "http://www.color.org",
"sRGB IEC61966-2.1", new FileInputStream(INTENT)));
pdfDocument.addFileAttachment(
"ZUGFeRD invoice", dom.toXML(), "ZUGFeRD-invoice.xml",
PdfName.ApplicationXml, new PdfDictionary(), PdfName.Alternative);
pdfDocument.setTagged();
HtmlConverter.convertToPdf(
new ByteArrayInputStream(html), pdfDocument, getProperties());
The getProperties() method looks like this:
public ConverterProperties getProperties() {
if (properties == null) {
properties = new ConverterProperties()
.setBaseUri("resources/zugferd/");
}
return properties;
}
You can find other examples on how to use HTML to PDF here: pdfHTML add-on (read the introduction).
Note that you are using an old version of iText. The examples I shared are using iText 7. There's a huge difference between iText 5 and iText 7.

pdf form fields empty after filling them with itext on android

In my android app I fill the formfields from a pdffile, using itextg like this:
PdfReader reader = new PdfReader(this.templateFile);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(this.targetFile));
AcroFields form = stamper.getAcroFields();
for (String key : values.keySet()) {
form.setField(key, values.get(key));
}
stamper.setFormFlattening(true);
stamper.close();
I can see, that the value of the formfields are actually set, when debugging and inspecting the stamper. But as soon I open the targetFile all of my fields are empty.
If I do not flatten my form, the values remain in the fields, which makes me believe the value would also be there in the flattend pdf but simply not displayed.
Btw, using FormFiller form the itext demos (http://itextpdf.com/itext-android-demos) the same pdf works really fine!

This could be caused by different things.
Not the correct iTextG version
See Appearance issues with pdf interactive forms using iText where you'll find this answer:
This seems to be a bug on some versions of iText. I had the same problem with iTextSharp version 5.5.5 and it was solved after I upgraded to version 5.5.9.
The form doesn't know it has to generate the appearances
See Editable .pdf fields disappear (but visible on field focus) after save with evince where the problem is solved by changing the appearance setting:
form.put(PdfName.NEEDAPPEARANCES, PdfBoolean.PDFTRUE);
Or see iText 5.5 fails to fill form where iText is instructed to create the appearances:
af.setGenerateAppearances(true);
I would start with af.setGenerateAppearances(true); first.

how can I write java code with syntax highlighting using pdfbox

I am trying to create a java project that simply prints a project source code, be it java, php, c++ and others.
I can create the PDF just fine with iText, but now I need some kind of highlighting the java code I read the same way a code editor like sublime highlights. I discovered pdfbox: a library for creating/manipulating PDF files, but I can't find how to highlight code text(like sublime does) by using this library. Any help?

Copying from another SO question : highlight text using pdfbox when it's location in the pdf is known
PDDocument doc = PDDocument.load(/*path to the file*/);
PDPage page = (PDPage)doc.getDocumentCatalog.getAllPages.get(i);
List annots = page.getAnnotations;
PDAnnotationTextMarkup markup = new PDAnnotationTextMarkup(PDAnnotationTextMarkup.Su....);
markup.setRectangle(/*your PDRectangle*/);
markup.setQuads(/*float array of size eight with all the vertices of the PDRectangle in anticlockwise order*/);
annots.add(markup);
doc.save(/*path to the output file*/);