Call scala function in java

FunctionUtil.scala

package chapter1
 
object FunctionUtil {
  def testFunction(f: Int => Int): Int = f(5)
 
  val list = (1 to 100).toList
 
  def filter(func: Int => Boolean): List[Int] =
    list.filter(func)
}
 
abstract class AbstractFunction1ForJava[X, Y] extends (X => Y) {
}
 
// JavaFunction.java
public class JavaFunction {
    public static void main(String[] args) {
        AbstractFunction1ForJava func = new AbstractFunction1ForJava<Integer, Boolean>() {
            public  Boolean apply(Integer argument) {
                return argument > 3 && argument < 8;
            }
        };
        System.out.println(FunctionUtil.filter(func));
    }
}