Attach text to highlight in a PDF

import java.awt.geom.Rectangle2D;
import java.io.File;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

import javax.management.MXBean;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationTextMarkup;
import org.apache.pdfbox.util.PDFTextStripperByArea;

public class Test {

    public static void main(String[] args) {

        try {
            PDDocument pddDocument = PDDocument.load(new File("./sample.pdf"));
            List allPages = pddDocument.getDocumentCatalog().getAllPages();
            for (int i = 0; i < allPages.size(); i++) {
                PDPage page = (PDPage) allPages.get(i);
                List<PDAnnotation> la = page.getAnnotations();
                for (PDAnnotation anot : la) {
                    if (anot instanceof PDAnnotationTextMarkup) {
                        System.out.println("Highlight found");
                        processHighlight((PDAnnotationTextMarkup) anot);
                        System.out.println("====");
                    }
                }
                pddDocument.save(new File("./result.pdf"));
            }
            pddDocument.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

    }

    private static void processHighlight(PDAnnotationTextMarkup highlight)
            throws IOException {
        System.out.println(highlight.getRectangle());
        float[] quads = highlight.getQuadPoints();
        PDFTextStripperByArea stripper = new PDFTextStripperByArea();
        PDRectangle pagesize = highlight.getPage().findMediaBox();
        System.out.println("Points: " + quads.length);
        for (int i = 0; i < quads.length; i++)
            System.out.println(quads[i]);

        for (int i = 0; i < quads.length; i += 8) {
            stripper.setSortByPosition(true);
            Rectangle2D.Float rect = new Rectangle2D.Float(quads[i] - 1,
                    pagesize.getHeight() - quads[i + 1], quads[i + 6]
                            - quads[i], quads[i + 1] - quads[i + 7]);
            stripper.addRegion("" + i, rect);
        }
        stripper.extractRegions(highlight.getPage());
        List<String> lines = new LinkedList<String>();
        for (String region : stripper.getRegions())
            lines.add(stripper.getTextForRegion(region));

        // Format text and set it as comment of the annotation
        String highlightText = "";
        for (String line : lines)
            highlightText = highlightText + line;
        highlight.setContents(highlightText);
    }
}