How can i add an image into an existing and specific pdf page (Itext)?

Question

I'm developing a "program" that create barcode and insert them on the original pdf.

This is my code:

package com.mycompany.barcodeinserter;

import com.itextpdf.io.image.ImageData;
import com.itextpdf.io.image.ImageDataFactory;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Image;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.parser.PdfTextExtractor;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;

import java.util.Scanner;
import javax.imageio.ImageIO;

import net.sourceforge.barbecue.output.OutputException;
import org.krysalis.barcode4j.impl.int2of5.Interleaved2Of5Bean;
import org.krysalis.barcode4j.output.bitmap.BitmapCanvasProvider;

/**
 *
 * @author ale
 */
public class main {

    public static void main(String[] args) throws OutputException {
        
        try {
            PrintWriter out = new PrintWriter("codici.txt");
            PdfWriter writer = new PdfWriter("/Users/ale/Documents/natale.pdf");
            PdfReader reader = new PdfReader("/Users/ale/Documents/natale.pdf");
            PdfDocument pdfDoc = new PdfDocument(writer); 
            Document document = new Document(pdfDoc); 
            int z = reader.getNumberOfPages();
            String page;
            ArrayList<String> codici = new ArrayList<String>();
            for (int i = 1; i <= z; i++) {
                countchar contatore = new countchar();
                page = PdfTextExtractor.getTextFromPage(reader, i);
                Scanner scanner = new Scanner(page);
                System.out.println("Pagina:" + i + "\n");
                while (scanner.hasNextLine()) {
                    String line = scanner.nextLine();
                    if (line.contains("cod")) {
                        String lineasucces = scanner.nextLine();
                        System.out.println(lineasucces.replaceAll("[^0-9]", ""));
                        //countchar contatoredue = new countchar(lineasucces.replaceAll("[^0-9]", ""));
                        switch (contatore.conta(line.replaceAll("[^0-9]", ""))) {
                            case 12:
                                System.out.println(contatore.usingSplitMethod(line.replaceAll("[^0-9]", ""), 6));
                                for (String element : contatore.usingSplitMethod(line.replaceAll("[^0-9]", ""), 6)) {
                                    if ((element != "") && (element.length() > 4)) {
                                        codici.add(element);
                                    }
                                }
                                break;
                            default:
                                System.out.println(contatore.usingSplitMethod(line.replaceAll("[^0-9]", ""), 13));
                                for (String element : contatore.usingSplitMethod(line.replaceAll("[^0-9]", ""), 13)) {
                                    if ((element != "") && (element.length() > 4)) {
                                        codici.add(element);
                                    }
                                }
                                break;
                        }

                        switch (contatore.conta(lineasucces.replaceAll("[^0-9]", ""))) {
                            case 12:
                                for (String element : contatore.usingSplitMethod(lineasucces.replaceAll("[^0-9]", ""), 6)) {
                                    if ((element != "") && (element.length() > 4)) {
                                        codici.add(element);
                                    }
                                }
                                break;
                            default:
                                for (String element : contatore.usingSplitMethod(lineasucces.replaceAll("[^0-9]", ""), 13)) {
                                    if ((element != "") && (element.length() > 4)) {
                                        codici.add(element);
                                    }
                                }
                                break;
                        }

                        /*
                        if (line.endsWith("")) {
                            System.out.println(contatore.usingSplitMethod(scanner.nextLine().replaceAll("[^0-9]", "").replaceAll("[^0-9]", ""), 13));
                            try {
                                switch (contatore.conta()) {
                                    case 12:
                                        System.out.println(contatore.usingSplitMethod(scanner.nextLine().replaceAll("[^0-9]", ""), 6));
                                        for (String element : contatore.usingSplitMethod(scanner.nextLine().replaceAll("[^0-9]", ""), 6)) {
                                            if ((element != "") && (element.length() > 4)) {
                                                codici.add(element);
                                            }
                                        }
                                        break;
                                    default:
                                        System.out.println(contatore.usingSplitMethod(scanner.nextLine().replaceAll("[^0-9]", ""), 13));
                                        for (String element : contatore.usingSplitMethod(scanner.nextLine().replaceAll("[^0-9]", ""), 13)) {
                                            if ((element != "") && (element.length() > 4)) {
                                                codici.add(element);
                                            }
                                        }
                                        break;
                                }

                            } catch (NoSuchElementException e) {
                                System.out.println(e);
                            }

                        }
                         */
                    }
                }

            }
            //BarcodeGenerator generator;
            int i = 0;
            for (String element : codici) {
                //generator = new BarcodeGenerator(EncodeTypes.EAN_13, "" + element);
                //generator.getParameters().setResolution(400);
                //generator.save("" + element + ".png");
                out.println(element);
                i++;
            }
            out.close();

            File file2 = new File("codici.txt");
            BufferedReader br = new BufferedReader(new FileReader(file2));

            String st;

            while ((st = br.readLine()) != null) {
                Interleaved2Of5Bean bean = new Interleaved2Of5Bean();
                bean.setHeight(10d);
                bean.doQuietZone(false);
                OutputStream out2 = new java.io.FileOutputStream(new File(st + ".png"));
                BitmapCanvasProvider provider = new BitmapCanvasProvider(out2, "image/x-png", 110, BufferedImage.TYPE_BYTE_GRAY, false, 0);
                bean.generateBarcode(provider, st);
                provider.finish();
                BufferedImage barcodeImage = provider.getBufferedImage();
                ImageIO.write(barcodeImage, "png", out2);
            }
                                        
            System.out.println("\n\n");
            System.out.println(codici);
            System.out.println(i);
            
            while ((st = br.readLine()) != null) { //here i tried to insert that but i'm stuck
                for (int j = 1; j <= z ; j++) {
                    String page2 = PdfTextExtractor.getTextFromPage(reader, j);
                    if (page2.contains(st)) {
                        ImageData imgdata = ImageDataFactory.create(st+".png");
                        Image image1 = new Image(imgdata);
                    }
                
                }
            }
            
            
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

I figured out how to create them but i didn't found anything on internet that helps me to add it into a specific page but only into all of the pages or only into a new page (which is not my purpose). Thank you for the helping (sorry if my english is not perfect :) ).

Answer 1

Here is an example how you can add either a barcode or an image to the existing page

import com.itextpdf.barcodes.BarcodePDF417;
import com.itextpdf.kernel.geom.Rectangle;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
import com.itextpdf.kernel.pdf.canvas.wmf.WmfImageData;
import java.io.IOException;

public class Main {
    public static void main(String[] args) throws IOException {
        String filename = "barcodeOnCustomPage.pdf";
        PdfReader reader = new PdfReader(filename);
        PdfWriter writer = new PdfWriter("out_" + filename);
        PdfDocument document = new PdfDocument(reader, writer);

        //Add barcode to the existing page
        String text = "Sample text for barcode";
        BarcodePDF417 barcode = new BarcodePDF417();
        barcode.setCode(text);
        barcode.placeBarcode(new PdfCanvas(document.getPage(1)), null);

        //Add image to the existing page
        new PdfCanvas(document.getPage(1)).addImageFittedIntoRectangle(new WmfImageData("example.wmf"),
                new Rectangle(200, 0, 0.1f, 0.1f), false);

        document.close();
    }
}