Many a times we use static methods or constants in our class. For example if you are writing a math library, there are chances that you would need to use lot of math functions from java.lang.Math. for example to calculate the nth power of x you would do
y = Math.pow(x,3);
pow is a static method in the Math class. if you use lot of such Math functions then it makes sense to statically import the Math class.
import static java.lang.Math.*;
If you do this you can directly use the math functions
You can also import a specific function or constant
This statement imports just the pow function.
However, it is advisable to use static imports sparingly since they may render the code difficult to read and maintain.