See Documentation
The static import declaration is
analogous to the normal import
declaration. Where the normal import
declaration imports classes from
packages, allowing them to be used
without package qualification, the
static import declaration imports
static members from classes, allowing
them to be used without class
qualification.So when should you use static import?
Very sparingly! Only use it when you’d
otherwise be tempted to declare local
copies of constants, or to abuse
inheritance (the Constant Interface
Antipattern). In other words, use it
when you require frequent access to
static members from one or two
classes. If you overuse the static
import feature, it can make your
program unreadable and unmaintainable,
polluting its namespace with all the
static members you import. Readers of
your code (including you, a few months
after you wrote it) will not know
which class a static member comes
from. Importing all of the static
members from a class can be
particularly harmful to readability;
if you need only one or two members,
import them individually. Used
appropriately, static import can make
your program more readable, by
removing the boilerplate of repetition
of class names.