Is it possible to declare a variable in Gradle usable in Java?

Question

Is it possible to declare a variable in Gradle usable in Java ? Basically I would like to declare some vars in the build.gradle and then getting it (obviously) at build time

Answer 1

I'm using

buildTypes.each {
    it.buildConfigField 'String', 'GoogleMapsApiKey', "\"$System.env.GoogleMapsApiKey\""
}

Its based on Dennis's answer but grabs its from an environment variable.