In the previous chapter, we discussed how to add pages to a PDF document. In this chapter, we will discuss how to add text to an existing PDF document.
You can add contents to a document using the PDFBox library, this provides you a class named PDPageContentStream which contains the required methods to insert text, images, and other types of contents in a page of a PDFDocument.
Following are the steps to create an empty document and add contents to a page in it.
You can load an existing document using the load() method of the PDDocument class. Therefore, instantiate this class and load the required document as shown below.
File file = new File("Path of the document"); PDDocument doc = document.load(file);
You can get the required page in a document using the getPage() method. Retrieve the object of the required page by passing its index to this method as shown below.
PDPage page = doc.getPage(1);
You can insert various kinds of data elements using the object of the class PDPageContentStream. You need to pass the document object and the page object to the constructor of this class therefore, instantiate this class by passing these two objects created in the previous steps as shown below.
PDPageContentStream contentStream = new PDPageContentStream(doc, page);
While inserting text in a PDF document, you can specify the start and end points of the text using the beginText() and endText() methods of the PDPageContentStream class as shown below.
contentStream.beginText(); ……………………….. code to add text content ……………………….. contentStream.endText();
Therefore, begin the text using the beginText() method as shown below.
contentStream.beginText();
Using the newLineAtOffset() method, you can set the position on the content stream in the page.
//Setting the position for the line contentStream.newLineAtOffset(25, 700);
You can set the font of the text to the required style using the setFont() method of the PDPageContentStream class as shown below. To this method you need to pass the type and size of the font.
contentStream.setFont( font_type, font_size );
You can insert the text into the page using the ShowText() method of the PDPageContentStream class as shown below. This method accepts the required text in the form of string.
contentStream.showText(text);
After inserting the text, you need to end the text using the endText() method of the PDPageContentStream class as shown below.
contentStream.endText();
Close the PDPageContentStream object using the close() method as shown below.
contentstream.close();
After adding the required content, save the PDF document using the save() method of the PDDocument class as shown in the following code block.
doc.save("Path");
Finally, close the document using the close() method of the PDDocument class as shown below.
doc.close();
This example demonstrates how to add contents to a page in a document. Here, we will create a Java program to load the PDF document named my_doc.pdf, which is saved in the path C:/PdfBox_Examples/, and add some text to it. Save this code in a file with name AddingContent.java.
import java.io.File; import java.io.IOException; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.pdmodel.PDPage; import org.apache.pdfbox.pdmodel.PDPageContentStream; import org.apache.pdfbox.pdmodel.font.PDType1Font; public class AddingContent { public static void main (String args[]) throws IOException { //Loading an existing document File file = new File("C:/PdfBox_Examples/my_doc.pdf"); PDDocument document = PDDocument.load(file); //Retrieving the pages of the document PDPage page = document.getPage(1); PDPageContentStream contentStream = new PDPageContentStream(document, page); //Begin the Content stream contentStream.beginText(); //Setting the font to the Content stream contentStream.setFont(PDType1Font.TIMES_ROMAN, 12); //Setting the position for the line contentStream.newLineAtOffset(25, 500); String text = "This is the sample document and we are adding content to it."; //Adding text in the form of string contentStream.showText(text); //Ending the content stream contentStream.endText(); System.out.println("Content added"); //Closing the content stream contentStream.close(); //Saving the document document.save(new File("C:/PdfBox_Examples/new.pdf")); //Closing the document document.close(); } }
Compile and execute the saved Java file from the command prompt using the following commands.
javac AddingContent.java java AddingContent
Upon execution, the above program adds the given text to the document and displays the following message.
Content added
If you verify the PDF Document new.pdf in the specified path, you can observe that the given content is added to the document as shown below.