PDFBox - Merging Multiple PDF Documents

In the previous chapter, we have seen how to split a given PDF document into multiple documents. Let us now learn how to merge multiple PDF documents as a single document.

Merging Multiple PDF Documents

You can merge multiple PDF documents into a single PDF document using the class named PDFMergerUtility class, this class provides methods to merge two or more PDF documents in to a single PDF document.

Following are the steps to merge multiple PDF documents.

Step 1: Instantiating the PDFMergerUtility class

Instantiate the merge utility class as shown below.

PDFMergerUtility PDFmerger = new PDFMergerUtility();

Step 2: Setting the destination file

Set the destination files using the setDestinationFileName() method as shown below.

PDFmerger.setDestinationFileName("D:/Projects/PDFBox/PdfBox_Examples/merged.pdf");

Step 3: Setting the source files

Set the source files using the addSource() method as shown below.

File file = new File("path of the document")
PDFmerger.addSource(file);

Step 4: Merging the documents

Merge the documents using the mergeDocuments() method of the PDFmerger class as shown below.

PDFmerger.mergeDocuments();

Example - Merging Multiple PDF Documents

Suppose, we have two PDF documents sample1.pdf and sample2.pdf, in the path D:/Projects/PDFBox/PdfBox_Examples/ as shown below.

This example demonstrates how to merge the above PDF documents. Here, we will merge the PDF documents named sample1.pdf and sample2.pdf in to a single PDF document merged.pdf. Save this code in a file with name PDFBoxDemo.java.

PDFBoxDemo.java

package com.tutorialspoint.pdfbox;

import org.apache.pdfbox.multipdf.PDFMergerUtility; 

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

public class PDFBoxDemo {
   public static void main(String[] args) throws IOException {
      File file1 = new File("D:/Projects/PDFBox/PdfBox_Examples/sample1.pdf");       
      File file2 = new File("D:/Projects/PDFBox/PdfBox_Examples/sample2.pdf");    
		
      //Instantiating PDFMergerUtility class
      PDFMergerUtility PDFmerger = new PDFMergerUtility();
		
      //Setting the destination file
      PDFmerger.setDestinationFileName("D:/Projects/PDFBox/PdfBox_Examples/merged.pdf");
		
      //adding the source files
      PDFmerger.addSource(file1);
      PDFmerger.addSource(file2);
		
      //Merging the two documents
      PDFmerger.mergeDocuments();
      System.out.println("Documents merged");
   }
}

Output

Compile and run the code to verify the following output −

Documents merged

If you verify the given path, you can observe that a PDF document with name merged.pdf is created and this contains the pages of both the source documents as shown below.