如何將圖像添加到現有的特定 pdf 頁面 (Itext) 中？

Question

我正在開發一個創建條形碼並將它們插入原始pdf的“程序”。

這是我的代碼：

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();
        }
    }

}

我想出了如何創建它們，但我沒有在互聯網上找到任何可以幫助我將其添加到特定頁面但僅添加到所有頁面或僅添加到新頁面的內容（這不是我的目的）。 謝謝你的幫助（對不起，如果我的英語不完美:)）。

Answer 1

這是一個如何將條形碼或圖像添加到現有頁面的示例

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();
    }
}