iText tutorial: Merge & Split PDF files using iText JAR
- By Viral Patel on June 11, 2009
In previous article about Generating PDF files using iText JAR, Kiran Hegde had described a nice and basic way of generating PDF files in Java using iTest JAR. It is a great starter tutorial for those who wants to start working with iText.
In one of the requirement, I had to merge two or more PDF files and generate a single PDF file out of it. I thought of implementing the functionality from scratch in iText, but then thought to google it and see if already someone have written code for what I was looking for.
As expected, I got a nice implementation of java code that merges 2 or more PDF files using iText jar. I thought of dissecting the code in this post and give credit to original author of the post.
Merge PDF files in Java using iText JAR
So here we go. First let us see the code.
package net.viralpatel.itext.pdf;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import com.lowagie.text.Document;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfImportedPage;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfWriter;
public class MergePDF {
public static void main(String[] args) {
try {
List<InputStream> pdfs = new ArrayList<InputStream>();
pdfs.add(new FileInputStream("c:\\1.pdf"));
pdfs.add(new FileInputStream("c:\\2.pdf"));
OutputStream output = new FileOutputStream("c:\\merge.pdf");
MergePDF.concatPDFs(pdfs, output, true);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void concatPDFs(List<InputStream> streamOfPDFFiles,
OutputStream outputStream, boolean paginate) {
Document document = new Document();
try {
List<InputStream> pdfs = streamOfPDFFiles;
List<PdfReader> readers = new ArrayList<PdfReader>();
int totalPages = 0;
Iterator<InputStream> iteratorPDFs = pdfs.iterator();
// Create Readers for the pdfs.
while (iteratorPDFs.hasNext()) {
InputStream pdf = iteratorPDFs.next();
PdfReader pdfReader = new PdfReader(pdf);
readers.add(pdfReader);
totalPages += pdfReader.getNumberOfPages();
}
// Create a writer for the outputstream
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA,
BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
PdfContentByte cb = writer.getDirectContent(); // Holds the PDF
// data
PdfImportedPage page;
int currentPageNumber = 0;
int pageOfCurrentReaderPDF = 0;
Iterator<PdfReader> iteratorPDFReader = readers.iterator();
// Loop through the PDF files and add to the output.
while (iteratorPDFReader.hasNext()) {
PdfReader pdfReader = iteratorPDFReader.next();
// Create a new page in the target for each source page.
while (pageOfCurrentReaderPDF < pdfReader.getNumberOfPages()) {
document.newPage();
pageOfCurrentReaderPDF++;
currentPageNumber++;
page = writer.getImportedPage(pdfReader,
pageOfCurrentReaderPDF);
cb.addTemplate(page, 0, 0);
// Code for pagination.
if (paginate) {
cb.beginText();
cb.setFontAndSize(bf, 9);
cb.showTextAligned(PdfContentByte.ALIGN_CENTER, ""
+ currentPageNumber + " of " + totalPages, 520,
5, 0);
cb.endText();
}
}
pageOfCurrentReaderPDF = 0;
}
outputStream.flush();
document.close();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (document.isOpen())
document.close();
try {
if (outputStream != null)
outputStream.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
}
}
If you see what the code does is pretty simple.
- In main() method, we create a List of InputStream objects that points to all the input PDF files we need to merge
- We call MergePDF.concatPDFs() static method passing list of input PDFs, OutputStream object for merged output PDF and a boolean flag that represents whether you need to include page numbers at the end of each page as command line arguments
- In concatPDFs() method, first we convert List of InputStream objects to List of PdfReader objects in first while loop. And also we keep count of the total pages in all the input PDF files.
- Next we create BaseFont object using BaseFont.createFont() method. This will be the font for writing page numbers
- Next we create output objects to write our merged PDF file using Document class object and PdfWriter.getInstance() method
- Finally we write all the input PDFs into merged output PDF iterating each PDF and then writing each page of it in two while loops
- And then, close all the streams and clear all the buffers. Good boys do this
So now we know how to merge PDF files into one, let us see the way to split a PDF file or extract a part of PDF into another PDF.
Split PDF files in Java using iText JAR
Let us see the code.
/**
* @author viralpatel.net
*
* @param inputStream Input PDF file
* @param outputStream Output PDF file
* @param fromPage start page from input PDF file
* @param toPage end page from input PDF file
*/
public static void splitPDF(InputStream inputStream,
OutputStream outputStream, int fromPage, int toPage) {
Document document = new Document();
try {
PdfReader inputPDF = new PdfReader(inputStream);
int totalPages = inputPDF.getNumberOfPages();
//make fromPage equals to toPage if it is greater
if(fromPage > toPage ) {
fromPage = toPage;
}
if(toPage > totalPages) {
toPage = totalPages;
}
// Create a writer for the outputstream
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
PdfContentByte cb = writer.getDirectContent(); // Holds the PDF data
PdfImportedPage page;
while(fromPage <= toPage) {
document.newPage();
page = writer.getImportedPage(inputPDF, fromPage);
cb.addTemplate(page, 0, 0);
fromPage++;
}
outputStream.flush();
document.close();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (document.isOpen())
document.close();
try {
if (outputStream != null)
outputStream.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
}
In above code, we have created a method splitPDF () that can be used to extracts pages out of a PDF and write it into another PDF. The code is pretty much self explanatory and is similar to the one to merge PDF files.
Thus, if you need to split an input.pdf (having 20 pages) into output1.pdf (1-12 pages of input.pdf) and output2.pdf (13-20 of input.pdf), you can call the above method as follow:
public static void main(String[] args) {
try {
MergePDF.splitPDF(new FileInputStream("C:\\input.pdf"),
new FileOutputStream("C:\\output1.pdf"), 1, 12);
MergePDF.splitPDF(new FileInputStream("C:\\input.pdf"),
new FileOutputStream("C:\\output2.pdf"), 13, 20);
} catch (Exception e) {
e.printStackTrace();
}
}
Feel free to bookmark the code and share it if you feel it will be useful to you 
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Hi ,
I want to split the pdf if my pdf exceeds the given size.
For Example,
If my pdf size is 12MB,I want to split the pdf in to 5MB parts.
So i need to split the pdf in to 3, 5MB,5MB,2MB respectively.
Pls let me know whether this is possible.
Regards,
Prem
@Prem, This example only splits the PDF on basis of page numbers. I will definitely try to write code for splitting pdf on basis of size and update you.
I would like to paste my code here to split a PDF based on bookmarks using iText. All my bookmarks are on level1. I based my code sample on the example on this page, and that’s why I would like to place my code here. I couldn’t really find any example of splitting a PDF based on bookmarks with iText, so I thought it could help other people if I put my code on this page:
public static void splitPDFByBookmarks(String pdf, String outputFolder){ try { PdfReader reader = new PdfReader(pdf); //List of bookmarks: each bookmark is a map with values for title, page, etc List<HashMap> bookmarks = SimpleBookmark.getBookmark(reader); for(int i=0; i<bookmarks.size(); i++){ HashMap bm = bookmarks.get(i); HashMap nextBM = i==bookmarks.size()-1 ? null : bookmarks.get(i+1); //In my case I needed to split the title string String title = ((String)bm.get("Title")).split(" ")[2]; log.debug("Titel: " + title); String startPage = ((String)bm.get("Page")).split(" ")[0]; String startPageNextBM = nextBM==null ? "" + (reader.getNumberOfPages() + 1) : ((String)nextBM.get("Page")).split(" ")[0]; log.debug("Page: " + startPage); log.debug("------------------"); extractBookmarkToPDF(reader, Integer.valueOf(startPage), Integer.valueOf(startPageNextBM), title + ".pdf",outputFolder); } } catch (IOException e) { log.error(e.getMessage()); } } private static void extractBookmarkToPDF(PdfReader reader, int pageFrom, int pageTo, String outputName, String outputFolder){ Document document = new Document(); OutputStream os = null; try{ os = new FileOutputStream(outputFolder + outputName); // Create a writer for the outputstream PdfWriter writer = PdfWriter.getInstance(document, os); document.open(); PdfContentByte cb = writer.getDirectContent(); // Holds the PDF data PdfImportedPage page; while(pageFrom < pageTo) { document.newPage(); page = writer.getImportedPage(reader, pageFrom); cb.addTemplate(page, 0, 0); pageFrom++; } os.flush(); document.close(); os.close(); }catch(Exception ex){ log.error(ex.getMessage()); }finally { if (document.isOpen()) document.close(); try { if (os != null) os.close(); } catch (IOException ioe) { log.error(ioe.getMessage()); } } }Thanks Goblin for the code. I appreciate your effort of sharing this here.
i had downloaded iText jar 5.0.1 but it do not contain com.lowagie.text.table package what should i do?? i want to create table dynamically in pdf page..
Viral,
I was searching pdf splittig on the basis of size(excedding a given size say > 10 MB). Prem was also looking for the same last year.Just checking if you got an opportunity to write on this.
Thanks for your help
Puru
Viral
Thanks for posting the code here.
i was searching for the code to read a image and parse it can you post the code
Viral : If you already found the script for splitting pdfs by page size, it would be VERY handy
Thx in advance
Hi Viral,
By any chance is it possible to split the pages randomly? E.g. I have a PDF document of 20 pages and now I was a new PDF containing only 2nd, 5th, 11th and 16th page of the original document.
Thanks in advance.
Vishnu.
Thank for sharing
hi viral…can you provide sample code to generate thumbnails to a pdf page
nice coding…:)its wrks for me always in 1 shoot viral
@Swati – Thanks
Hi Viral Patel,
Did you manage to develop sample code to split PDFs based on size? i.e. Splitting a 8MB file into 2MB PDFs.
Regards,
Edwin
Hi Viral , I got the following errors:
Exception in thread “main” java.lang.OutOfMemoryError: Java heap space
at java.io.ByteArrayOutputStream.write(Unknown Source)
at com.itextpdf.text.pdf.RandomAccessFileOrArray.InputStreamToArray(Rand
omAccessFileOrArray.java:182)
at com.itextpdf.text.pdf.RandomAccessFileOrArray.(RandomAccessFile
OrArray.java:172)
at com.itextpdf.text.pdf.PdfReader.(PdfReader.java:237)
at com.itextpdf.text.pdf.PdfReader.(PdfReader.java:248)
at MergePDF.splitPDF(split.java:38)
at ShivaPdf.main(split.java:87)
How to resolve them.
Dimitri asked:
“Viral : If you already found the script for splitting pdfs by page size, it would be VERY handy”
I found the answer here:
http://java-x.blogspot.com/2006/11/merge-pdf-files-with-itext.html#comment-3167256311373072651
document.setPageSize(pdfReader.getPageSizeWithRotation(pageOfCurrentReaderPDF));
document.newPage();
I.e., immediately before creating a new page, set the page size to the page size (and orientation) of the page you are reading in. The only issue to be aware of is the PDF has to be (I believe) version 1.5 or higher. You’ll get errors trying to open PDFs saved as 1.4.
pdfWriter.setPdfVersion(PdfWriter.PDF_VERSION_1_5);
Hey
I have used your code for merging few pdf files but I still have a problem to merge files that carry different sizes!
I have try to had a command to set the page size
document.newPage();
pageOfCurrentReaderPDF++;
currentPageNumber++;
document.setPageSize(pdfReader.getPageSize(pageOfCurrentReaderPDF));
Thanks, for the helpful code!
Natalie
Very good code for merging & splitting….
good work itext…………exactly suits my requirement.
hi,thanks for your coding ,but I still have a problem to merge files that carry different sizes!
how could i solve it? some page is large while other is small.I am tired with it.help!
Does anybody have any examples for splitting a PDF at bookmarks that exist at a level 2? The code provided by Goblin_Queen works great for level 1 bookmarks, but I’m not quite sure how to expand that to level 2 bookmarks as the resulting hashmap for the “Kids” do not contain page information.
HashMap bm = bookmarks.get(i);
List kids = (List) bm.get(“Kids”);
The kids hashmap does not have the “Page” defined.
You could reduce the number of lines by using PdfStamper class.
PdfReader pdfReader = new PdfReader(fileDialog.FileName);
FileOutputStream fout = new FileOutputStream(“C:\\output1.pdf”);
PdfStamper splitter = new PdfStamper(pdfReader, fout);
pdfReader.SelectPages(“1 – 10″);
splitter.Close();
pdfReader.Close();
very useful code for all guys who r in initial stage thank u very much
I tried the concatPDFs code. It concatenates two files OK. But, it does not copy the signatures that were in the files. It also does not copy text data fields.
thank you for the great tutorial and comments. They help me a lot, to write my own split function