The Java Tutorials have been written for JDK 8. Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.
See Dev.java for updated tutorials taking advantage of the latest releases.
See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.

Create a JAR File Containing the Class File

Next, create a JAR file containing the Count.class file. Type the following in your command window:

jar cvf Count.jar Count.class

This creates a JAR file, Count.jar, and places the Count.class file inside it.