Java로 PDF 파일에 워터마킹하는 방법

IronPDF - Java PDF Library

IronPDF Java Edition is a library for working with PDFs in Java. It offers fast and accurate operations, making it an excellent choice for many PDF file-related tasks like extracting text from PDFs, extracting images from PDFs, merging PDF files, and splitting PDFs. It is built on the capabilities of IronPDF for .NET, ensuring reliable functionality.

With the IronPDF library, you can convert HTML, URL, and strings into PDF documents using popular open standard document types such as HTML, CSS, JS, JPG, and PNG. The library generates PDFs with HTML to PDF conversion with precise pixel-perfect rendering and utilizes the latest technology.

Prerequisites

Before getting started, make sure you have the following prerequisites in place:

1. Java Development Kit (JDK) installed on your machine.
2. A Java IDE (Integrated Development Environment) such as Eclipse, NetBeans, or IntelliJ IDEA.
3. IronPDF library added as a dependency in your Java project. You can include it by referencing the appropriate Maven artifact or by manually importing the JAR file. You can download it from the IronPDF home page and include it in your project.

Setting up the Project

1. Create a new Java project in your chosen IDE and include the IronPDF library as a dependency. You can do this by either adding the Maven artifact to your project's pom.xml file or by importing the JAR file manually.

2. Add the IronPDF library to your project using the dependency manager.

   # Install IronPDF through Maven or another package manager

   # Install IronPDF through Maven or another package manager

   SHELL

3. Add the following necessary imports to your Java source file(s):

   import com.ironsoftware.ironpdf.PdfDocument;
   import com.ironsoftware.ironpdf.stamp.*;
   
   import java.io.IOException;
   import java.nio.file.Paths;

   import com.ironsoftware.ironpdf.PdfDocument;
   import com.ironsoftware.ironpdf.stamp.*;
   
   import java.io.IOException;
   import java.nio.file.Paths;

   JAVA

Loading the PDF Document

To begin, load the existing PDF document on which you want to add the watermark, or create a new PDF file using the renderHtmlAsPdf method. IronPDF provides convenient methods to open and manipulate PDF files. The following code example will load the example.pdf file as a PdfDocument object:

// Load an existing PDF document
PdfDocument pdf = PdfDocument.fromFile(Paths.get("example.pdf"));

// Load an existing PDF document
PdfDocument pdf = PdfDocument.fromFile(Paths.get("example.pdf"));

Adding Watermark to PDF File

IronPDF allows you to add various types of watermarks to your PDF documents, including text watermarks and image watermarks. Let's explore both options:

// Apply a text watermark to the PDF
pdf.applyWatermark("<h1 style=\"color:red\">Confidential</h1>", 50, VerticalAlignment.MIDDLE, HorizontalAlignment.CENTER);
// Save the modified PDF document with the applied watermark
pdf.saveAs("textwatermarked.pdf");

// Apply a text watermark to the PDF
pdf.applyWatermark("<h1 style=\"color:red\">Confidential</h1>", 50, VerticalAlignment.MIDDLE, HorizontalAlignment.CENTER);
// Save the modified PDF document with the applied watermark
pdf.saveAs("textwatermarked.pdf");

// Apply an image watermark to the PDF
pdf.applyWatermark("<img src='assets/images/iron-pdf-logo.jpg'>", 50, VerticalAlignment.MIDDLE, HorizontalAlignment.CENTER);
// Save the modified PDF document with the applied watermark
pdf.saveAs("imagewatermarked.pdf");

// Apply an image watermark to the PDF
pdf.applyWatermark("<img src='assets/images/iron-pdf-logo.jpg'>", 50, VerticalAlignment.MIDDLE, HorizontalAlignment.CENTER);
// Save the modified PDF document with the applied watermark
pdf.saveAs("imagewatermarked.pdf");

Make Watermarked PDF using Stamper Class

IronPDF for Java provides a Stamper class, which can be used to add text and image watermarks using HtmlStamper, ImageStamper, and TextStamper classes. The Stamper class provides more flexibility over the applyWatermark method.

// Create a text stamper for watermarking
TextStamper stamper = new TextStamper("Confidential");
stamper.setFontColor("#FF0000");
stamper.setFontSize(60);
stamper.setFontFamily("Times New Roman");
stamper.setHorizontalAlignment(HorizontalAlignment.CENTER);
stamper.setVerticalAlignment(VerticalAlignment.MIDDLE);
stamper.setOpacity(30);
stamper.setRotation(45);
// Apply the stamper to the PDF
pdf.applyStamp(stamper);
// Save the modified PDF document with the watermark
pdf.saveAs("textwatermarked2.pdf");

// Create a text stamper for watermarking
TextStamper stamper = new TextStamper("Confidential");
stamper.setFontColor("#FF0000");
stamper.setFontSize(60);
stamper.setFontFamily("Times New Roman");
stamper.setHorizontalAlignment(HorizontalAlignment.CENTER);
stamper.setVerticalAlignment(VerticalAlignment.MIDDLE);
stamper.setOpacity(30);
stamper.setRotation(45);
// Apply the stamper to the PDF
pdf.applyStamp(stamper);
// Save the modified PDF document with the watermark
pdf.saveAs("textwatermarked2.pdf");

// Create an image stamper for watermarking
ImageStamper stamper = new ImageStamper("assets/images/iron-pdf-logo.jpg");
stamper.setHorizontalAlignment(HorizontalAlignment.CENTER);
stamper.setVerticalAlignment(VerticalAlignment.MIDDLE);
stamper.setOpacity(30);
stamper.setStampBehindContent(true);
stamper.setRotation(45);
// Apply the stamper to the PDF
pdf.applyStamp(stamper);
// Save the modified PDF document with the watermark
pdf.saveAs("imagewatermarked.pdf");

// Create an image stamper for watermarking
ImageStamper stamper = new ImageStamper("assets/images/iron-pdf-logo.jpg");
stamper.setHorizontalAlignment(HorizontalAlignment.CENTER);
stamper.setVerticalAlignment(VerticalAlignment.MIDDLE);
stamper.setOpacity(30);
stamper.setStampBehindContent(true);
stamper.setRotation(45);
// Apply the stamper to the PDF
pdf.applyStamp(stamper);
// Save the modified PDF document with the watermark
pdf.saveAs("imagewatermarked.pdf");

Conclusion

This article explored how to add watermarks to PDF documents using IronPDF. With IronPDF's intuitive APIs, you can easily incorporate text or image watermarks into your PDF files, enhancing their security and branding. Experiment with different customization options using the Stamper class to achieve the desired watermarking effects. Now, you can confidently protect and personalize your PDF documents in your Java applications.

For detailed guidance and examples on utilizing IronPDF for Java, you can refer to the code examples, which provide helpful resources and demonstrations.

IronPDF is free for development purposes and offers commercial licensing options for commercial use. To learn more about the licensing details, you can visit the IronPDF Licensing Guide.

You can also get a free API license in a free trial license for commercial use. To obtain the IronPDF software, you can download it from the official IronPDF for Java website.