import com.itextpdf.kernel.pdf.PdfDocument;  
import com.itextpdf.kernel.pdf.PdfReader;  
import com.itextpdf.kernel.pdf.PdfWriter;  
import com.itextpdf.layout.Document;  
import com.itextpdf.layout.element.Image;  
import com.itextpdf.io.image.ImageDataFactory;  
  
import java.io.IOException;  
  
public class PDFImageFiller {  
    public static void main(String[] args) {  
        String inputFilePath = "path/to/input.pdf";  
        String outputFilePath = "path/to/output.pdf";  
        String imagePath = "path/to/image.jpg";  
  
        try {  
            PdfReader pdfReader = new PdfReader(inputFilePath);  
            PdfWriter pdfWriter = new PdfWriter(outputFilePath);  
            PdfDocument pdfDocument = new PdfDocument(pdfReader, pdfWriter);  
            Document document = new Document(pdfDocument);  
  
            Image image = new Image(ImageDataFactory.create(imagePath));  
            document.add(image);  
  
            document.close();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }  
}

import org.apache.pdfbox.pdmodel.PDDocument;  
import org.apache.pdfbox.pdmodel.PDPage;  
import org.apache.pdfbox.pdmodel.PDPageContentStream;  
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;  
  
import java.io.*;  
  
public class ImageToPdf {  
    public static void main(String[] args) throws IOException {  
        PDDocument doc = new PDDocument();  
        try {  
            // 圖片文件路徑列表  
            String[] imageFilePaths = {"image1.jpg", "image2.jpg", "image3.jpg"};  
  
            for (String imageFilePath : imageFilePaths) {  
                // 創(chuàng)建新的一頁(yè)  
                PDPage page = new PDPage(PDPage.PAGE_SIZE_A4);  
                doc.addPage(page);  
  
                // 獲取內(nèi)容流  
                PDPageContentStream contentStream = new PDPageContentStream(doc, page);  
  
                // 讀取圖片文件并添加到PDF中  
                File imageFile = new File(imageFilePath);  
                PDImageXObject image = PDImageXObject.createFromFile(imageFile.getAbsolutePath(), doc);  
                float imageWidth = image.getWidth();  
                float imageHeight = image.getHeight();  
                float scaleX = PDPage.PAGE_SIZE_A4.getWidth() / imageWidth;  
                float scaleY = PDPage.PAGE_SIZE_A4.getHeight() / imageHeight;  
                float scale = Math.min(scaleX, scaleY);  
                contentStream.drawImage(image, 0, 0, imageWidth * scale, imageHeight * scale);  
                contentStream.close();  
            }  
  
            // 保存PDF文件  
            doc.save("output.pdf");  
        } finally {  
            doc.close();  
        }  
    }  
}