import com.google.common.collect.*; public class Main { public static void main(String[] args) { ImmutableList<String> list = ImmutableList.of("a", "b", "c"); Iterable<String> filteredList = Iterables.filter(list, s -> s.startsWith("a")); String joinedString = Joiner.on(", ").join(filteredList); System.out.println(joinedString); } }