Answer by smftr for Java Hashmap: How to get key from value?

let see my example

Map<String, String> mapPeopleAndCountry = new HashMap<>();mapPeopleAndCountry.put("Matis", "Lithuania");mapPeopleAndCountry.put("Carlos", "Honduras");mapPeopleAndCountry.put("Teboho", "Lesotho");mapPeopleAndCountry.put("Marielos", "Honduras");List<String> peopleInHonduras = mapPeopleAndCountry.keySet()    .stream()    .filter(r -> mapPeopleAndCountry.get(r)                .equals("Honduras"))    .stream(Collectors.toList());// will return ["Carlos", "Marielos"]

Note: untested, may contains typo