As I expected, the answer was staring me right in the face, I just needed someone to point it out for me.
PDDocument document = new PDDocument();
PDPage page = new PDPage(PDPage.PAGE_SIZE_LETTER);
document.addPage(page);
PDPageContentStream content = new PDPageContentStream(document,page);
//generate data for first page
content.close();
//if number of results exceeds what can fit on the first page
page = new PDPage(PDPage.PAGE_SIZE_LETTER);
document.addPage(page);
content = new PDPageContentStream(document,page);
//generate data for second page
content.close();
Thanks to @mkl for the answer.