Apache CXF
· Apache CXF is an open-source services framework that aids in
the development of services using front-end programming APIs, like JAX-WS
and JAX-RS.
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 cxf-2.6.17-TomEE.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.