PDFBox - JavaScript in PDF Document

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In the previous chapter, we have learnt how to insert image into a PDF document. In this chapter, we will discuss how to add JavaScript to a PDF document.

Adding JavaScript to a PDF Document

You can add JavaScript actions to a PDF document using the PDActionJavaScript class. This represents a JavaScript action.

Following are the steps to add JavaScript actions to an existing PDF document.

Step 1: Loading an Existing PDF Document

Load an existing PDF document using the static method loadPDF() of the Loader class. This method accepts a RandomAccessReadBufferedFile object as a parameter, since this is a static method you can invoke it using class name as shown below.

// Loading an existing document 
PDDocument document = Loader.loadPDF(
   new RandomAccessReadBufferedFile("D:/Projects/PDFBox/PdfBox_Examples/sample.pdf"));

Step 2: Creating the PDActionJavaScript Object

Instantiate the PDActionJavaScript object as shown below. To the constructor of this class, pass the required JavaScript in the form of String as shown below.

String javaScript = "app.alert( {cMsg: 'this is an example', nIcon: 3,"
   + " nType: 0,cTitle: 'PDFBox Javascript example' } );";       
PDActionJavaScript PDAjavascript = new PDActionJavaScript(javaScript);

Step 3: Embedding Java script in the Document

Embed the required string to the PDF document as shown below.

document.getDocumentCatalog().setOpenAction(PDAjavascript);

Step 4: Saving the Document

After adding the required content save the PDF document using the save() method of the PDDocument class as shown in the following code block.

document.save("Path");

Step 5: Closing the Document

Finally, close the document using close() method of the PDDocument class as shown below.

document.close();

Example - Inserting JavaScript in a PDF Document

Suppose, we have a PDF document named sample.pdf, in the path D:/Projects/PDFBox/PdfBox_Examples/ with empty pages as shown below.

This example demonstrates how to embed JavaScript in the above mentioned PDF document. Here, we will load the PDF document named sample.pdf and embed JavaScript in it. Save this code in a file with name PDFBoxDemo.java.

package com.tutorialspoint.pdfbox;

import java.io.IOException;

import org.apache.pdfbox.Loader;
import org.apache.pdfbox.io.RandomAccessReadBufferedFile;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.interactive.action.PDActionJavaScript;

public class PDFBoxDemo {
   public static void main(String args[]) throws IOException {

      // Loading an existing document 
      PDDocument document = Loader.loadPDF(
         new RandomAccessReadBufferedFile("D:/Projects/PDFBox/PdfBox_Examples/my_doc.pdf")); 

      String javaScript = "app.alert( {cMsg: 'this is an example', nIcon: 3,"
         + " nType: 0, cTitle: 'PDFBox Javascript example} );";

      //Creating PDActionJavaScript object 
      PDActionJavaScript PDAjavascript = new PDActionJavaScript(javaScript);

      //Embedding java script
      document.getDocumentCatalog().setOpenAction(PDAjavascript);

      System.out.println("Data added to the given PDF");

      //Saving the document
      document.save("D:/Projects/PDFBox/PdfBox_Examples/new.pdf");

      //Closing the document
      document.close();
   }
}

Output

Compile and run the code to verify the following output −

Data added to the given PDF

If you try to open the document new.pdf it will display an alert message as shown below.