Merge Multiple PDFs to Single PDF

We can merge two or more PDFs to a single PDF using PDFBox.

In this tutorial, we will learn the steps required to merge multiple PDF documents to a single PDF.

To Merge Multiple PDFs to Single PDF, use PDFMergerUtility.mergeDocuments(File file) method. You may merge an many number of files as required.

Steps – Merge Multiple PDF Files

Following is a step by step guide to merge multiple PDF files.

Step 1: Load PDF Files

Load all the source PDF files you wish to merge.

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File file1 = new File("/home/tk/sample_1.pdf");
File file2 = new File("/home/tk/sample_2.pdf");
File file3 = new File("/home/tk/sample_3.pdf");Merge Documents.

Step 2: Instantiate PDFMergerUtility

PDFMergerUtility Class contains routines to merge PDFs.

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PDFMergerUtility pdfMerger = new PDFMergerUtility();

Step 3: Set Destination

Set path to destination file using PDFMergerUtility.setDestinationFileName(String fileName) method.

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pdfMerger.setDestinationFileName("/home/tk/sample_pdf.pdf");

Step 4: Add all PDFs

Add all the source PDF files to be merged, to PDFMergerUtility using PDFMergerUtility.addSource() method.

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pdfMerger.addSource(file1);
pdfMerger.addSource(file2);
pdfMerger.addSource(file3);

Add all the source pdf files one by one in the sequence you would like to find in the final merged PDF file.

Step 5: Merge Documents

And finally call the method PDFMergerUtility.mergeDocuments() to merge all the documents.

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pdfMerger.mergeDocuments(null);

Complete Java Program

MergePDFsExample.java

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import org.apache.pdfbox.multipdf.PDFMergerUtility;

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

public class MergePDFsExample {

	public static void main(String[] args) throws IOException {
	      // load pdf files to be merged
	      File file1 = new File("/home/tk/sample_1.pdf");
	      File file2 = new File("/home/tk/sample_2.pdf");
	      File file3 = new File("/home/tk/sample_3.pdf");
	         
	      // instantiatE PDFMergerUtility class
	      PDFMergerUtility pdfMerger = new PDFMergerUtility();

	      // set destination file path
	      pdfMerger.setDestinationFileName("/home/tk/sample_pdf.pdf");

	      // add all source files, to be merged, to pdfMerger
	      pdfMerger.addSource(file1);
	      pdfMerger.addSource(file2);
	      pdfMerger.addSource(file3);

	      // merge documents
	      pdfMerger.mergeDocuments(null);

	      System.out.println("PDF Documents merged to a single file");
	}
}

Output

PDF Documents merged to a single file