IntelliSense is actually Microsoft’s implementation of auto-completion, used in Visual Studio. Eclipse has a similar feature. It’s called Content Assist. If for some reason yours is turned off (like the way how mine magically did) , here’s how to re-enable it.
Go to Window->Preferences->Java->Editor->Content Assist->Advanced.
The one you’d be most interested in is Java Proposals. It list the functions and properties of an object whenever you type a ‘.’ after an object name.