Documentation — SwingToPDF

Installation

Maven

pom.xml

<dependency>
    <groupId>com.seaglassfoundry</groupId>
    <artifactId>swingtopdf</artifactId>
    <version>1.0.1</version>
</dependency>

Gradle (Kotlin DSL)

build.gradle.kts

implementation("com.seaglassfoundry:swingtopdf:1.0.1")

Gradle (Groovy DSL)

build.gradle

implementation 'com.seaglassfoundry:swingtopdf:1.0.1'

Note: Apache PDFBox 3.x is pulled in automatically as a transitive dependency. You do not need to declare it separately.

JVM Flags

SwingToPDF uses --add-opens to access Swing internals for accurate font resolution and rendering. Add these flags to your application's JVM arguments:

Module path

--add-opens java.desktop/javax.swing=com.seaglassfoundry.swingtopdf
--add-opens java.desktop/java.awt=com.seaglassfoundry.swingtopdf
--add-opens java.desktop/sun.font=com.seaglassfoundry.swingtopdf

Classpath (no modules)

--add-opens java.desktop/javax.swing=ALL-UNNAMED
--add-opens java.desktop/java.awt=ALL-UNNAMED
--add-opens java.desktop/sun.font=ALL-UNNAMED

Without these flags? The library still works, but font resolution falls back to scanning system font directories instead of reading JVM-internal font paths. This is slower on the first export and may miss fonts loaded via Font.createFont().

Basic Usage

Export any JComponent to a PDF file with just a few lines:

Java

import com.seaglassfoundry.swingtopdf.SwingPdfExporter;
import com.seaglassfoundry.swingtopdf.api.PageSize;
import com.seaglassfoundry.swingtopdf.api.Orientation;

// Any JComponent — a JPanel, JTable, JTabbedPane, etc.
JPanel panel = buildYourUI();

SwingPdfExporter.from(panel)
    .pageSize(PageSize.A4)
    .orientation(Orientation.PORTRAIT)
    .margins(36, 36, 36, 36)    // 0.5 inch on all sides
    .title("My First PDF")
    .export(Path.of("output.pdf"));

Exporting to a Stream

Write the PDF to a network response, byte array, or any other OutputStream:

Java

try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
    SwingPdfExporter.from(panel)
        .pageSize(PageSize.LETTER)
        .export(baos);

    byte[] pdfBytes = baos.toByteArray();
    // send to HTTP response, save to database, etc.
}

Fillable Form Fields (AcroForm)

Produce a PDF with interactive form fields — text inputs, checkboxes, dropdowns — with a single method call:

Java

SwingPdfExporter.from(myForm)
    .pageSize(PageSize.LETTER)
    .enableAcroForm()
    .export(Path.of("form.pdf"));

Supported components: JTextField, JCheckBox, JRadioButton, JComboBox, JTextArea, and JPasswordField.

Export Modes

SwingToPDF offers two export modes:

DATA_REPORT (default) — exports all data: every table row, every tab, the full scroll content. Automatically paginates.
UI_SNAPSHOT — captures only what is currently visible on screen.

Java

import com.seaglassfoundry.swingtopdf.api.ExportMode;

SwingPdfExporter.from(panel)
    .exportMode(ExportMode.UI_SNAPSHOT)
    .export(Path.of("screenshot.pdf"));

Headless / CI Environments

SwingToPDF works in headless environments. Make sure your component has been sized before exporting:

Java

// Option 1: explicit size
panel.setSize(800, 600);

// Option 2: pack a frame (triggers layout)
JFrame frame = new JFrame();
frame.setContentPane(panel);
frame.pack();

Requirements

Java 17 or later
Apache PDFBox 3.x (included as transitive dependency)

Javadoc & Full Reference

Javadoc is published alongside the artifact on Maven Central. Comprehensive documentation covering pagination, headers/footers, font embedding, and the full component reference is coming soon.