I used Java code to split a PDF file by delimiter. To do this, I used the Apache PDFBox package. I provide this code here:

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.Loader;
import org.apache.pdfbox.text.PDFTextStripper;

import java.io.File;
import java.io.IOException;

public class PDFSplitter {	
    public static void main(String[] args) {
        try {
        	String splitter = "%%SPLIT";
            PDDocument document =  Loader.loadPDF(new File(args[0]));
            int countPages = document.getNumberOfPages();
            PDDocument newDocument = new PDDocument();
            for (int page = 0; page < countPages; page++) {
                newDocument.addPage((PDPage) document.getPage(page));
                PDFTextStripper pdfTextStripper = new PDFTextStripper();
                String text = pdfTextStripper.getText(newDocument);
                if (text.contains(splitter)) {
                	String fileName = text.substring(text.indexOf(splitter));
                	fileName = fileName.substring(splitter.length()+1, fileName.indexOf('\r'))+".pdf";
                	File f = new File(fileName);
                	if (f.exists()) {
                    String outputFileName = fileName;
                    newDocument = new PDDocument();
        } catch (IOException e) {

I use the string "%%SPLIT" as a separator (it can be replaced with yours) and expect that there after space will be a string finished '\r' which I will use as the file name.

I export my class to the runnable JAR file and use the command line for the splitter execution here:

java -jar pdfsplitter.jar < file name >