Java Archive (JAR)

Last Updated: April 14, 2014

Definition - What does Java Archive (JAR) mean?

Java archive (JAR) is a file format that contains bundled Java class files along with associated image/sound files, resources and metadata. It is usually a single, compressed file mostly used for supplying the necessary Java libraries and application software on a Java programming platform.

The JAR file format is similar to the tape archive (TAR) file format used in Unix.

Techopedia explains Java Archive (JAR)

A JAR file also may be used in the following ways:

As a building block in Java applications
As a deployment unit for Java plug-ins, applets or components For packaging Java components and dependent resources

JAR file features include the following:

Mostly compressed into a ZIP file format and identified with the file .jat file extension
Can be executable
One can sign in on JAR file contents for more security.
Have a lower download time, especially those related to applets and Java Web Start
Highly compressed and provide efficient storage for the bundled Java files
Support package versioning and package version consistency
Support portability
Java Development Kit (JDK) provides a JAR tool that helps perform basic JAR file tasks.
In a JDK, a utility program with a JAR is provided. A programmer can use this to create, extract or perform any permitted operations on the JAR file.
Date and time stamp are stored during the creation of a JAR file.
Using JAR files, a Java application can be initiated in an enterprise.
When used on the Web, a JAR file may contain an applet and accompany a Web page.