OpenAPI 3.1
· This feature enables users to discover and understand REST APIs exposed by web applications and Liberty components that use the OpenAPI 3.0 specification.
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 openapi-3.1-23.0.0.8.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.