awt-graphics-rest-quickstart

Web service to watermark images

This quickstart demonstrates a use case for Quarkus AWT extension.

There is a single POST endpoint that consumes a multipart form data and returns an octet stream with a watermarked PNG image. For the sake of brevity, regardless of the image type posted, the service always returns a PNG image.

Quarkus AWT extension enables a set of ImageIO and AWT functionality in Quarkus Native images. See the extension documentation and tests to learn the available scope. Given the nature of native libraries in JDK implementing various image processing algorithms, venturing outside the tested scope might result in native image build time or runtime failure.

Additional system dependencies

Note microdnf command installing fontconfig library in Dockerfile.jvm and Dockerfile.legacy-jar to support jvm mode. Both freetype and fontconfig libraries are needed for native mode in Dockerfile.native.

Usage with curl

e.g.

curl -F "image=@/tmp/my_image.jpg"  http://localhost:8080/watermark --output /tmp/result.png

Watermarks the given image with some text in the top left corner and a Quarkus icon in the right bottom corner.

Usage with a client code

See ImageResourceTest.java. The test is executed in native mode with:

./mvnw clean verify -Pnative

To run native tests locally, a JDK 17+ with Mandrel (or GraalVM) 21.3+ is required. Additionally, freetype-devel and fontconfig libraries must be installed.

What the result looks like

This is an example of what this quick start does to an image: