Flatten JsonObject

recursiveFlattening.java

private Stream<Map.Entry<String, Object>> recursiveFlattening(String key, Map.Entry<String, Object> entry) {
    String jsonKey = entry.getKey();
    Object jsonElement = entry.getValue();

    if(key != null)
      jsonKey = key + "/" + jsonKey;

    final String res = jsonKey;

    if (jsonElement instanceof JsonObject) {
      return ((JsonObject) jsonElement).stream()
          .flatMap(item -> recursiveFlattening(res, item));
    } else if (jsonElement instanceof JsonArray) {
      return ((JsonArray) jsonElement).stream()
          .map(v -> Map.entry("", v))
          .flatMap(item -> recursiveFlattening(res, item));
    } else {
      return Stream.of(Map.entry(res, entry.getValue()));
    }
  }