// "Collapse loop with stream 'collect()'" "true-preview" import java.util.List; import java.util.stream.Collectors; public class Test { static String test(List list) { String sb = list.stream().filter(s -> !s.isEmpty()).map(String::trim).collect(Collectors.joining("", "asdsad" + "bar", "")); //comment return sb.length() == 0 ? null : sb; } }