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 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.
The Java™ Archive (JAR) file format enables you to bundle multiple files into a single archive file. Typically a JAR file contains the class files and auxiliary resources associated with applets and applications.
The JAR file format provides many benefits:
This lesson has four sections:
This section shows you how to perform basic JAR-file operations, and how to run software that is bundled in JAR files.
This section explains manifest files and how to customize them so you can do such things as seal packages and set an application's entry point.
This section shows you how to digitally sign JAR files and verify the signatures of signed JAR files.
This section introduces you to some of the JAR-handling features of the Java platform. The JAR file format is an important part of the Java platform's extension mechanism. You can learn more about that aspect of JAR files in the The Extension Mechanism trail of this tutorial.
Test what you've learned about JAR.
The documentation for the Java Development Kit (JDK) includes information about the Jar tool: