Command line utility based on deegree3 to generate preview graphics from SLD (Styled Layer Descriptor) files.
You can download the latest release here or build it yourself.
git clone https://github.com/JuergenWeichand/deegree-sld-preview.git
cd deegree-sld-preview/
mvn clean compile assembly:single
Usage: java -jar deegree-sld-preview.jar sld_file|sld_dir