How To Merge PDF Online?
Upload & Edit Your PDF Document
Save, Download, Print, and Share
Sign & Make It Legally Binding
Easy-to-use PDF software
How do I detect different PDF files merged into a single PDF file and split the respective PDFs into separate PDFs?
You can use Spire.PDF for Java to merge/split PDF files. Click the below links to see the relevant tutorials. Merge PDF. Split PDF.
Merge PDF: All You Need to Know
How it works (PDF).