org.refcodes:refcodes-data-ext
· Artifact providing extensions such as resources for the refcodes-data
artifact. Resources may be images, sounds, videos, maze-maps and so on.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window refcodes-data-ext-3.2.8.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.