枚举反转

枚举反转

第一种 使用Guava的Maps实现

private static final Map<Integer, JobWeekEnum> LOOKUP = Maps.uniqueIndex(
            Arrays.asList(JobWeekEnum.values()),JobWeekEnum::getCnWeek
    );


    @Nullable
    public static JobWeekEnum reversal(int cnWeek) {
        return LOOKUP.get(cnWeek);
    }

第二种 使用Hutool

public static Integer resolve(String desc) {
        AttrSourceEnum by = EnumUtil.getBy(AttrSourceEnum.class, key -> key.getDesc().equals(desc));
        if (by == null) {
            return null;
        }
        return by.getCode();
    }

第三种使用循环

public static String resolve(Integer code) {
        for (DeviceStatusEnum deviceStatusEnum : DeviceStatusEnum.values()) {
            if (deviceStatusEnum.getCode().equals(code)){
                return deviceStatusEnum.getDesc();
            }
        }
        return null;
    }

第四种使用Map

private static Map<Integer, PizzaStatus> timeToDeliveryToEnumValuesMapping = new HashMap<>();

static {
    for (PizzaStatus pizzaStatus : PizzaStatus.values()) {
        timeToDeliveryToEnumValuesMapping.put(
          pizzaStatus.getTimeToDelivery(),
          pizzaStatus
        );
    }
}

第五种使用Stream

Optional<PizzaStatus> pizzaStatus = Arrays.stream(PizzaStatus.values())
  .filter(p -> p.getTimeToDelivery() == timeToDeliveryForOrderedPizzaStatus)
  .findFirst();

assertThat(pizzaStatus).hasValue(PizzaStatus.ORDERED);