How to automate PDF form-filling in Java

Question

I am doing some "pro bono" development for a food pantry near where I live. They are inundated with forms and paperwork, and I would like to develop a system that simply reads data from their MySQL server (which I set up for them on a previous project) and feeds data into PDF versions of all the forms they are required to fill out. This will help them out enormously and save them a lot of time, as well as get rid of a lot of human errors that are made when filling out these forms.

Not knowing anything about the internals of PDF files, I can foresee two avenues here:

Harder Way: It is possible to scan a paper document, turn it into a PDF, and then have software that "fills out" the PDF simply by saying "add text except blah to the following (x,y) coordinates..."; or
Easier Way: PDF specification already allows for the construct of "fields" that can be filled out; this way I just write code that says "add text excerpt blah to the field called *address_value*...", etc.

So my first question is: which of the two avenues am I facing? Does PDF have a concept of "fields" or do I need to "fill out" these documents by telling the PDF library the pixel coordinates of where to place data?

Second, I obviously need an open source (and Java) library to do this. iText seems to be a good start but I've heard it can be difficult to work with. Can anyone lend some ideas or general recommendations here? Thanks in advance!

user_10007797 · Answer

public void fillPDF()
{
    
     try {
            PDDocument pDDocument = PDDocument.load(new File("D:/pdf/pdfform.pdf")); // pdfform.pdf is input file
            PDAcroForm pDAcroForm = pDDocument.getDocumentCatalog().getAcroForm();
            
                    
         PDField field = pDAcroForm.getField("Given Name Text Box"); 

          field.setValue("firstname"); 
          field = pDAcroForm.getField("Family Name Text Box");
          field.setValue("lastname");
          field = pDAcroForm.getField("Country Combo Box");
          field.setValue("Country");
          System.out.println("country combo" );
          field = pDAcroForm.getField(" Driving License Check Box");
          
          field = pDAcroForm.getField("Favourite Colour List Box");
        System.out.println("country combo"+ field.isRequired());
          pDDocument.save("D:/pdf/pdf-java-output.pdf");
             pDDocument.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
}

How to automate PDF form-filling in Java

3 Answers