J2SE 5.0 Instance---static introduction

j2se| static static introduction (static Import)


In the past we were going to use static variables from a class in another package, usually preceded by the corresponding class name:

Double r = Math.Cos (Math.PI * theta);

With static introduction, we can remove the previous class name, and the static introduction of the statement is this:

Import static Java.lang.Math.PI;



It must be noted that this is not the end of class math, but directly to the defined variable pi.

Static introduction is not only to static variables, but also to static methods. You can also use *, as shown in the following:

Import static java.lang.math.*;



Unless we have a high frequency of access to a static constant (or method), we should try to avoid using static introductions.