How to merge two PDFs using Java

Problem Description

How to merge two PDFs using Java.

Solution

Following is an example program to merge two pdf documents using Java.

import org.apache.pdfbox.multipdf.PDFMergerUtility; 
import org.apache.pdfbox.pdmodel.PDDocument;  

import java.io.File; 
import java.io.IOException;  

public class MergingPdfs { 
   public static void main(String[] args) throws IOException { 
      
      //Loading an existing PDF document 
      File file1 = new File("C:/pdfBox/sample1.pdf"); 
      PDDocument doc1 = PDDocument.load(file1); 

      File file2 = new File("C:/pdfBox/sample2.pdf"); 
      PDDocument doc2 = PDDocument.load(file2); 

      //Instantiating PDFMergerUtility class 
      PDFMergerUtility PDFmerger = new PDFMergerUtility();       

      //Setting the destination file 
      PDFmerger.setDestinationFileName("C:/pdfBox/merged.pdf"); 

      //adding the source files 
      PDFmerger.addSource(file1); 
      PDFmerger.addSource(file2); 

      //Merging the two documents 
      PDFmerger.mergeDocuments(); 
      System.out.println("Documents merged"); 

      //Closing the documents 
      doc1.close(); 
      doc2.close();           
   } 
}