String[] arrayDB = {"aa","bb","cc","dd","ee","gg"};
String[] arrayIn = {"ee","ff","gg"};
Set<String> bb = new HashSet<>(Arrays.asList(arrayIn));
List<String> same = Arrays.asList(arrayDB).stream().filter(i->!bb.add(i)).collect(Collectors.toList());
String[] arrayDB = {"aa","bb","cc","dd","ee","gg"};
String[] arrayIn = {"ee","ff","gg"};
Set<String> bb = new HashSet<>(Arrays.asList(arrayIn));
List<String> same = Arrays.asList(arrayDB).stream().filter(i->!bb.add(i)).collect(Collectors.toList());