JAVA [creating Jar files]

to create a jar file execute this command given below
jar cf jar-file input-file(s)

For more you can see this Creating JAR files


After creation you must specify the main class using menifest.

Ways to update a jar file with manifest......

I have created a text file as manifest like aaa.txt which contains
[Code]Main-class: Mainclassname[/Code]

then I have executed command given below
updating e jar file with main class

jar umf aaa.txt calender.jar
jar xvf calender.jar
type META-INF\MANIFEST.MF