如何使用 Java 为 PDF 中的图像添加水印

问题描述

如何使用 Java 为 PDF 中的图像添加水印

解决方案

以下是使用 Java 为 PDF 中的图像添加水印的程序。

import com.itextpdf.io.image.ImageDataFactory; 

import com.itextpdf.kernel.color.DeviceGray; 
import com.itextpdf.kernel.geom.Rectangle; 
import com.itextpdf.kernel.pdf.PdfDocument; 
import com.itextpdf.kernel.pdf.PdfWriter; 
import com.itextpdf.kernel.pdf.xobject.PdfFormXObject; 

import com.itextpdf.layout.Canvas; 
import com.itextpdf.layout.Document; 
import com.itextpdf.layout.element.Image; 
import com.itextpdf.layout.property.TextAlignment;  

public class AddingToImagesInPDF { 
   public static void main(String args[]) throws Exception { 
      String file = "C:/EXAMPLES/itextExamples/addingImageToPDF.pdf"; 

      //Creating a PdfDocument object 
      PdfDocument pdfDoc = new PdfDocument(new PdfWriter(file));     

      //Creating a Document object 
      Document doc = new Document(pdfDoc);        

      //Creating an Image         
      Image image = new Image(ImageDataFactory.create(
         "C:/EXAMPLES/itextExamples/logo.jpg")); 
      image.scaleToFit(400, 700); 

      //Creating template             
      PdfFormXObject template = new PdfFormXObject(new Rectangle(
         image.getImageScaledWidth(), image.getImageScaledHeight())); 
      
      Canvas canvas = new Canvas(template, pdfDoc).add(image); 
      String watermark = "Welcome to Tutorialspoint"; 
      canvas.setFontColor(DeviceGray.LIGHT_GRAY)      
         .showTextAligned(watermark, 100, 360, TextAlignment.CENTER);  

      //Adding template to document
      Image image1 = new Image(template);          
      doc.add(image1); 

      //Closing the document 
      doc.close();  
      System.out.println("Watermark added successfully..");  
   }  
}

输入

输出