How to link openhab and eclipse

I just started to contact openHAB,I would like to ask you how to link the openHAB and eclipse

If you mean Eclipse Smarthome Designer read this:

http://docs.openhab.org/configuration/editors.html#esh-designer

Thank you for answering my question ,what about eclipse IDE for java developers?

http://docs.openhab.org/developers/development/ide.html