fprint
· fprint is a small library providing fluent interfaces for building
structures which can be then parsed as XML, JSON, YAML using one of the
provided printers.
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 fprint-0.2.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.