import java.util.List;
import java.util.ArrayList;
import java.util.Set;
compileKotlin {
    kotlinOptions {
        languageVersion = "1.1"
        apiVersion = "1.1"
    }
}
import java.util.ArrayList
import java.util.HashSet
以上方法,可以解决Android Studio Unresolved Reference: List, arrayListOf, setOf错误。