NetBeans No Extension MIME Resolver Plugin
· Return a proper mime type from a shebang line or modeline of a file if the file extension is empty. (e.g. myscript)
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 netbeans-noext-mime-resolver-0.12.1.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.