Using .*; after importing a class

Using .*; after importing a class

I'm learning some java classes through the Java API and I'm just wondering
when you should be using the .*; after each import. Here is what I have
for the program so far.
import java.awt.GridLayout;
public class GridLayoutClass {
public static void main(String[] args){
GridLayout grid = new GridLayout(3, 4);
}
}