Creating a JAR File

The basic format of the command for creating a JAR file is:
jar cf jar-file input-file(s)
    
The options and arguments used in this command:

The c option indicates that you want to create a JAR file.

The f option indicates that you want the output to go to a file rather than to stdout. Always use this option.

jar-file is the name that you want the resulting JAR file to have.

You can use any filename for a JAR file.

By convention, JAR filenames are given a .jar extension.

The input-file(s) argument is a space-separated list of 1 or more files that you want to be placed in your JAR file.

The input-file(s) argument can contain the wildcard * symbol.

If any of the "input-files" are directories, the contents of those directories are added to the JAR archive recursively.

The options can appear in either order, but there must not be any space between them.

The command above generates a:

compressed JAR file and place it in the current directory

default manifest file for the JAR archive.
Additional options to the cf options of the basic command:
Option Description

v Produces verbose output on stdout while the JAR file is being built.
The verbose output tells the name of each file as it's added to the JAR file.

0 (zero) Indicates that you don't want the JAR file to be compressed.

M Indicates that the default manifest file should not be produced.
m
Used to include manifest information from an existing manifest file. The format for using this option is:
jar cmf existing-manifest jar-file input-file(s)
See Modifying a Manifest for more information about his option.

Option	Description
`v`	Produces verbose output on stdout while the JAR file is being built. The verbose output tells the name of each file as it's added to the JAR file.
`0` (zero)	Indicates that you don't want the JAR file to be compressed.
`M`	Indicates that the default manifest file should not be produced.
`m`	Used to include manifest information from an existing manifest file. The format for using this option is: jar cmf existing-manifest jar-file input-file(s) See Modifying a Manifest for more information about his option.

An Example

The JDK^TM demos include a simple TicTacToe applet.
This demo contains a class file, audio files, and images all in a directory called TicTacToe, having this structure:

The audio and images subdirectories contain sound files and GIF images used by the applet.
To package this demo into a single JAR file named TicTacToe.jar, run this command from inside the TicTacToe directory:
jar cvf TicTacToe.jar TicTacToe.class audio images

The audio and images arguments represent directories.
The Jar tool recursively places them and their contents in the JAR file.
The generated JAR file TicTacToe.jar is placed in the current directory.
Because the command used the v option for verbose output, you'd see something like this output when you run the command:

adding: TicTacToe.class (in=3825) (out=2222) (deflated 41%)
adding: audio/ (in=0) (out=0) (stored 0%)
adding: audio/beep.au (in=4032) (out=3572) (deflated 11%)
adding: audio/ding.au (in=2566) (out=2055) (deflated 19%)
adding: audio/return.au (in=6558) (out=4401) (deflated 32%)
adding: audio/yahoo1.au (in=7834) (out=6985) (deflated 10%)
adding: audio/yahoo2.au (in=7463) (out=4607) (deflated 38%)
adding: images/ (in=0) (out=0) (stored 0%)
adding: images/cross.gif (in=157) (out=160) (deflated -1%)
adding: images/not.gif (in=158) (out=161) (deflated -1%)

As you can see, the JAR file TicTacToe.jar is compressed.
You can turn off the compression feature by using the 0 (zero) option, so that the command would look like:

jar cvf0 TicTacToe.jar TicTacToe.class audio images

Uncompressed JAR files can generally be loaded more quickly than compressed files because the need to decompress the files during loading is eliminated.
However, there's a tradeoff in that download time over a network is longer for uncompressed files.

The Jar tool accepts arguments that use the wildcard * symbol.
As long as there are no unwanted files in the TicTacToe directory, you could use this command to construct the JAR file:

jar cvf TicTacToe.jar *

The Jar tool automatically adds a manifest file to the JAR archive with pathname META-INF/MANIFEST.MF.
See the Understanding the Manifest section for information about manifest files.

jar cf ImageAudio.jar images audio

The resulting JAR file would have this table of contents:

META-INF/MANIFEST.MF
images/cross.gif
images/not.gif
audio/beep.au
audio/ding.au
audio/return.au
audio/yahoo1.au
audio/yahoo2.au