Introduction to Java PDF Generation

Java developers often need to generate PDF documents, whether for structured reports, dynamic content, or custom graphics. This article provides an overview of the best tools for generating PDF documents in Java, along with examples and practical use cases.

Popular PDF Generation Tools in Java

There are several libraries available for generating PDF documents in Java, each with its own strengths and use cases. Here are a few popular options:

iText

iText is a widely used open-source Java library for creating and manipulating PDF files. It provides a high level of control over the content and layout of the document, making it suitable for complex and structured reports. iText supports a wide range of PDF features, including:

Text and images Watermarks and annotations Form fields and interactive elements Encryption and digital signatures

For example, you can design your report using a GUI designer, control the placement of bands, page breaks, and other elements, and then generate the PDF at runtime using a database ResultSet.

Apache PDFBox

Apache PDFBox is another popular open-source Java library for creating and manipulating PDF files. While it provides a lower-level API compared to iText, it offers excellent performance and support for a wide range of PDF features. It is particularly useful for applications requiring high-performance PDF processing.

Here's an example of how to generate a PDF using Apache PDFBox:

import org.apache.pdfbox.pdmodel.PDDocument;import ;import org.apache.pdfbox.pdmodel.PDPage;import org.apache.pdfbox.pdmodel.PDRectangle;import ;public class PDFGenerator {    public static void main(String[] args) {        try {            PDDocument document  new PDDocument();            PDPage page  new PDPage(PDRectangle.A4);            (page);            PDPageContentStream contentStream  new PDPageContentStream(document, page);            ();            (PDType1Font.HELVETICA_BOLD, 18);            (100, 700);            ("Hello, PDFBox!");            contentStream.endText();            // Add an image            PDImageXObject pdImage  ("", document);            contentStream.drawImage(pdImage, 100, 500, 100, 100);            ();            // Save and close the document            ("output.pdf");            ();        } catch (Exception e) {            ();        }    }}

JasperReports

JasperReports is a powerful Java-based reporting tool that can be used to generate PDF reports. It provides a robust report generation engine and supports a wide range of data sources, such as databases, Excel files, and more. JasperReports allows you to design your report layout using a user-friendly GUI and then generate the PDF at runtime.

Here's a simple example of generating a PDF using JasperReports:

import net.sf.jasperreports.engine.JRExporterParameter;import net.sf.jasperreports.engine.JasperExportManager;import net.sf.jasperreports.engine.JasperPrint;public class JasperReportExample {    public static void main(String[] args) {        try {            JasperPrint jasperPrint  // compile and fill the report from a database            JasperExportManager.exportReportToPdfFile(jasperPrint, "output.pdf");        } catch (Exception e) {            ();        }    }}

Examples and Use Cases

Depending on your specific requirements, different tools may be better suited for generating PDF documents in Java. Here are a few examples:

Structured Reports from a Database

If you need to generate structured reports, such as generating a print binary stream from a database ResultSet, you should use JasperReports. JasperReports can handle complex layouts with bands, page breaks, and other elements. At runtime, you feed the report a database ResultSet and the compiled report design, and you get back a PDF output.

Custom Graphics and Drawings

For applications that require custom graphics or drawings, you can use Apache PDFBox or Flying Saucer. In 2016, I used Apache XML Graphics Commons 2.0.1 for drawing custom graphics onto pages in a PDF. Here's a basic example of how to use Apache XML Graphics Commons for drawing into a PDF page:

import ;import ;import ;import org.apache.xmlgraphics.kf.flatten.KlioFlatten;import ;import ;import ;import ;public class PDFDrawingExample {    public static void main(String[] args) {        try {            KfServicesFactory kfServices  ();            Graphics2D graphics  ().traverse(new FixedHeightImageSource(200, 200), "", (200), kfServices);            // Drawing operations here, like , graphics.drawImage, etc.            graphics.dispose();            FileOutputStream fileOut  new FileOutputStream("output.pdf");            KlioFlatten.flatten(graphics, fileOut);            fileOut.flush();            ();            ("Successfully created PDF file");        } catch (IOException e) {            ();        }    }}

Conclusion

Choosing the best tool for generating PDF documents in Java largely depends on your specific requirements and preferences. For structured and dynamic reports, JasperReports is a powerful choice. For high-performance custom graphics, Apache PDFBox and Flying Saucer offer robust solutions. By understanding the strengths and use cases of these tools, you can select the most appropriate one for your Java PDF generation needs.