You can also use the wildcard form e.g. that lets you use all the methods in a class without the class name qualification, e.g.

import static java.lang.Math.*;

...

double y = cos(x) + tan(theta);

The wild card form is useful to give you unqualified access to all the enum constants or static finals of a class.

Sometimes you both import and import static, e.g.

import java.lang.Math;
import static java.lang.Math.sin;

...

double theta = Math.atan2( y, x );
double s = sin( g );