How to find classes in unimported packages?

In IDEA, when you input part of a classname or methodname and then press
CTRL+SPACE, IDE will gives a list of all similar classes or methods for you
to choose. However, these classes or methods are only available in the
imported packages.

I want to know how to find a class in JDK or 3rd Libraries. Far more, if
IDEA can support to popup a list of all classes it finds and allow us to
import it.

Such features can be find in Netbeans. When I input "BASE64" and then press
CTRL+SPACE, a list of all classes whose names include "BASE64", and if I
choose one, the such a class will be imported automaticly.

Hope to add such features to IDEA. thanks.

Netsesame.