How to import addons to Eclipse IDE [solved]

by doc here,

yes. we can git clone openhab2-addons project and import into Eclipse workspace.
And by run configurations, the addons show on plugins page under workspace.

However, if we want to use an addon instead of debug/develop it, we may want to import it into target platform.
I wonder whether this is already be done in some way automatically?
Thank you very much.

just add openhab2-addons/binding directory via target platform menu entry under plugin development.

I want to add the prexisting addon jar file org.openhab.ui.habmin_0.1.6.jar (that I downloaded from here) into a working openhab2 in the IDE.
Window -> Prefernces -> Plug-in Development -> Target Platform shows a Target Platform dialog box with an item selected in bold: openHAB Target Platform (Active) - /launch/ There is a button “Add” next to it but I’m not sure how to use it?
Following the instructions in here, I execute openhab and do see messages in the Console pane, and also http://localhost:8080 responds, but http://localhost:8080/habmin doesn’t come up.
I don’t know how to import the habmin jar addon properly. Can anyone help me on how to import this jar file into the eclipse, so that it’s taking effect in the project?