How to add a class to a .jar file

I have a Java program that has many .jar files.  I recently received two class files that need to be added to one of the .jar files.   How can I add these to a jar file?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Here is this explanation of it though. It goes into much more detail.
Mick BarryJava DeveloperCommented:
jar uf <class file name> <jar file name>

Make sure you include the class in its package/folder structure
Rowby Goren Makes an Impact on Screen and Online

Learn about longtime user Rowby Goren and his great contributions to the site. We explore his method for posing questions that are likely to yield a solution, and take a look at how his career transformed from a Hollywood writer to a website entrepreneur.

Mick BarryJava DeveloperCommented:
oops, wrong way around. should be:

jar uf <jar file name> <class file name>
To make it very very simple..

rename the file to .zip
open and extract with winzip or any zip software (a folder structure will be extracted)
copy your file in the required folder location
zip the folder back to the same name as your jar and you are done.

Remember the folder structure after zipping should be exactly the same as before for things to work.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
jbaird123Author Commented:
Thank you.
Thank you jbaird for the grade and the points.
Have a nice day.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.