Q:

Using pdfbox in java to overlay text onto previously created pdf document

I already have several PDF documents that have been created.  What I am attempting to do is by using PDFBox.  I need to put text into several places on these created documents but I do NOT want to modify the text that is within those areas.  For instance, there may be a a section as follows -
NAME: ______________________________
I will put text into that area, but I need the underline to remain the same length.  I believe the best solution would be to just create a textbox or similar that goes above the area so the line remains the same length. 
In other words, I do not want to edit the text inline so it will remain the same length.  I have no code for this as I am just attempting to understand the pdfbox package.  I have been looking for examples online, but most of them just show how to create a document and not how to update a previously document.  How do I do this? 

A:

I found the answer and wanted to share. 
In the pdfbox package there is a class called Overlay.  
    PDDocument pdfDocument = new Overlay();
    PDDocument final = pdfDocument.overlay(PDDocument firstDoc, PDDocument otherDoc);

firstDoc will be overlaid onto otherDoc.  Easy peasy.  I just didn't know where to look.