quarkusio/quarkus · error · UnsupportedOperationException

Printing is not supported with Quarkus AWT extension.

Error message

Printing is not supported with Quarkus AWT extension.

What it means

The Quarkus AWT extension supports only server-side, headless mode and explicitly cuts the dependency on printing. It substitutes sun.awt.windows.WToolkit.getPrintJob to throw UnsupportedOperationException whenever printing is attempted. This is intentional: java.awt.PrintJob is not available in Quarkus apps using the AWT extension.

Source

Thrown at extensions/awt/runtime/src/main/java/io/quarkus/awt/runtime/JDKSubstitutions.java:160

                        "filename.Wingdings=WINGDING.TTF\n";
                Files.writeString(configFile, minimalConfig, StandardCharsets.UTF_8);
            }
        } catch (IOException e) {
            throw new UncheckedIOException("Failed to write Windows " + configFile.toAbsolutePath(), e);
        }
    }
}

/**
 * Cut the dependency on Swing and Printing - we support server side, headless mode.
 * TODO: If an extension in Quarkiverse complains, we revisit it here.
 */
@TargetClass(className = "sun.awt.windows.WToolkit", onlyWith = IsWindows.class)
final class Target_sun_awt_windows_WToolkit {

    @Substitute
    public PrintJob getPrintJob(Frame frame, String jobtitle, Properties props) {
        throw new UnsupportedOperationException("Printing is not supported with Quarkus AWT extension.");
    }

    @Substitute
    public PrintJob getPrintJob(Frame frame, String jobtitle, JobAttributes jobAttributes, PageAttributes pageAttributes) {
        throw new UnsupportedOperationException("Printing is not supported with Quarkus AWT extension.");
    }
}

/**
 * Cut ties to windowing, desktop
 * TODO: If an extension in Quarkiverse complains, we revisit it here.
 */
@TargetClass(className = "sun.awt.windows.WObjectPeer", onlyWith = IsWindows.class)
final class Target_sun_awt_windows_WObjectPeer {
    @Substitute
    private static void initIDs() {
        // no-op, no pData, destroyed, target
    }

View on GitHub (pinned to e1c734241f)

Solutions

1. Remove or avoid the code path calling getPrintJob; render to images/streams instead
2. Configure the offending library to a non-printing (image/stream) output mode
3. Exclude printing-related dependencies that probe AWT printing at runtime

Example fix

// before
PrintJob job = Toolkit.getDefaultToolkit().getPrintJob(frame, "doc", props);
// after: render headlessly instead
BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = img.createGraphics();
component.paint(g);

if (Toolkit.getDefaultToolkit() instanceof sun.awt.windows.WToolkit) {
  throw new IllegalStateException("Printing is unsupported under Quarkus AWT extension");
}

static boolean printingSupported(GraphicsEnvironment env) {
  return !env.isHeadless(); // in Quarkus AWT it is always headless; treat printing as unsupported
}

When it happens

Trigger: Calling Toolkit.getDefaultToolkit().getPrintJob(frame, jobtitle, props) on a Windows JVM/native-image with the Quarkus AWT extension present — the substituted method always throws.

Common situations: A library that lazily resolves a PrintJob (some imaging/reporting libs probe printing); migrating a Swing app snippet into a Quarkus service; Windows-specific toolkit substitution triggering print code paths.

Related errors

• Failed to write Windows ${configFile.toAbsolutePath()}
• Add AWT Quarkus extension to enable Java2D/ImageIO. Addition
• Not Allowed
• .pfa font files are not supported. Use TrueType fonts, i.e.
• .pfb font files are not supported. Use TrueType fonts, i.e.

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/593c9d9fb59ed709. Report an issue: GitHub.