通过pdfbox将图像添加到pdf，但是在添加pdf后获得空白

问题描述

 import java.awt.image.BufferedImage;  
 import java.io.ByteArrayInputStream;  
 import java.io.File;  
 import java.io.IOException;  
 import java.util.Scanner;  
 import javax.imageio.ImageIO;  
 import org.apache.commons.codec.binary.Base64;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.net.MalformedURLException;
 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;

 public class One {
      /**  
       * @param args  
       */  
      public static void main(String[] args) throws IOException {
           // Todo Auto-generated method stub  
           Scanner s=new Scanner(system.in);  
           System.out.println("Enter base64 string to be converted to image");  
           String base64=s.nextLine();  
           byte[] base64Val=convertToImg(base64);
           writeBytetoImageFile(base64Val,"image.png");
           System.out.println("Saved the base64 as image in current directory with name image.png");
           addImagetoPDF();
      }
      public static byte[] convertToImg(String base64) throws IOException  
      {  
           return Base64.decodeBase64(base64);  
      }  
      public static void writeBytetoImageFile(byte[] imgBytes,String imgFileName) throws IOException  
      {  
           File imgFile = new File(imgFileName);
           BufferedImage img = ImageIO.read(new ByteArrayInputStream(imgBytes));
           ImageIO.write(img,"png",imgFile);
      }
      
      public static void addImagetoPDF() throws IOException {
          File file = new File("C:\\Users\\user\\Downloads\\Risk Template(RiskTemplate).pdf"); 
          PDDocument doc = PDDocument.load(file);  
          PDPage page = doc.getPage(0);
          PDImageXObject pdImage = PDImageXObject.createFromFile("D:\\Development\\Workspace\\1\\image.png",doc); 
          PDPageContentStream contents = new PDPageContentStream(doc,page);
          contents.drawImage(pdImage,5,5);     
          System.out.println("Image inserted");  
          contents.close();       
          doc.save("D:\\Development\\Workspace\\1\\Insertimage_OP.pdf"); 

          doc.close();
      }
 }

我正在从base64字符串创建图像，然后尝试将该图像附加到pdf。图像创建成功，并且也将图像添加到pdf中，但是pdf（输出）仅在角落处包含图像，并且原始pdf的内容现在为空白。

解决方法

正如MKL和Tilman在评论中所写，您必须使用

PDPageContentStream(document,page,AppendMode.APPEND,true,true);

public static void addImageToPDF() throws IOException {
          File file = new File("C:\\Users\\user\\Downloads\\Risk Template(RiskTemplate).pdf"); 
          PDDocument doc = PDDocument.load(file);  
          PDPage page = doc.getPage(0);
          PDImageXObject pdImage = PDImageXObject.createFromFile("D:\\Development\\Workspace\\1\\image.png",doc); 
          PDPageContentStream contents = new PDPageContentStream(doc,true);
          contents.drawImage(pdImage,5,5);     
          System.out.println("Image inserted");  
          contents.close();       
          doc.save("D:\\Development\\Workspace\\1\\InsertImage_OP.pdf"); 

          doc.close();
      }

免责声明：该答案由MKL / Tilman给出，但作为参考，答案比评论更“可见”。

java java pdfbox