How to create or update a jira issue programatically using Java

Hi I am trying to create a custom implementation for editing Jira issues for the Jira server version. Has anyone here done something along the lines of creating/ editing issues etc.
What I am looking for is a way to handle the JIRA objects to get this done.

I am very new to this, any help would be greatly appreciated!

The IssueService class is what you seek. https://docs.atlassian.com/software/jira/docs/api/7.8.0/com/atlassian/jira/bc/issue/IssueService.html

Thanks a lot, this does look like what I need!
Do you have any sample implementation/ examples by any chance? Also, what is the JAR that I need to import to be able to use these classes?
Thanks again!