Jar Files

Usage: jar {ctxu}[vfm0M] [jar-file] [manifest-file] [-C dir] files ...
Options:
    -c  create new archive
    -t  list table of contents for archive
    -x  extract named (or all) files from archive
    -u  update existing archive
    -v  generate verbose output on standard output
    -f  specify archive file name
    -m  include manifest information from specified manifest file
    -0  store only; use no ZIP compression
    -M  do not create a manifest file for the entries
    -i  generate index information for the specified jar files
    -C  change to the specified directory and include the following file
If any file is a directory then it is processed recursively.
The manifest file name and the archive file name needs to be specified
in the same order the 'm' and 'f' flags are specified.

Example 1: to archive two class files into an archive called classes.jar: 
       jar cvf classes.jar Foo.class Bar.class 

Example 2: use an existing manifest file 'mymanifest' and archive all the
           files in the foo/ directory into 'classes.jar': 
       jar cvfm classes.jar mymanifest -C foo/ .

Example 3: use an existing manifest file 'mymanifest' and archive all the
           class and source code files in this directory into 'classes.jar':
       jar cvfm classes.jar mymanifest *.class *.java

Manifest files

If you have an application bundled in a JAR file, you need some way to indicate which class within the JAR file is your application's entry point. Recall that the entry point is the class having a method with signature
public static void main(String[] args)
You provide this information with the Main-Class header, which has the general form:
Main-Class: classname
The value classname is the name of the class that is your application's entry point.

Example: If the entry point is in class HelloWorld, then this would be what would be in your manifest file:
Main-Class: HelloWorld
Manifest files can have any name.