javax.validation自定義日期範圍校驗註解操作

 // 前端傳字串如‘2020-07-13 09:09:09' springmvc接收並轉換為LocalDateTime型別
  @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
  private LocalDateTime endTime; 

 LocalDateTime now = LocalDateTime.now(); 
 // jdk8校驗傳入日期是否為一年內
 boolean flag = endTime.isBefore(now.plusYears(1))

/**
 * 日期時間範圍校驗註解，可作用於LocalDateTime or 字串型年月日時分秒（格式可通過pattern屬性指定）
 * 
 * @author meilin.huang
 * @date 2020-07-09 1:51 下午
 */
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.TYPE_USE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = DateTimeRange.DateTimeRangeValidator.class)
public @interface DateTimeRange {

  /**
   * 最小時間範圍（為負數即為前n unit）
   */
  int min() default 0;

  int max() default Integer.MAX_VALUE;

  /**
   * 時間單位 (年月日)
   */
  RangeUnit unit() default RangeUnit.DAYS;

  /**
   * 作用於字串時，指定的格式，包含年月日時分秒
   */
  String pattern() default "yyyy-MM-dd HH:mm:ss";

  /**
   * 是否忽略更小的單位，即比當前指定的unit更小的單位（如unit為Days，則忽略hours，minutes, second）
   */
  boolean ignoreLowerUnit() default false;

  /**
   * 錯誤提示
   */
  String message() default "日期時間錯誤";

  /**
   * 用於分組校驗
   */
  Class<?>[] groups() default {};
  Class<? extends Payload>[] payload() default {};
  class DateTimeRangeValidator implements ConstraintValidator<DateTimeRange, Object> {
    private DateTimeRange dateTimeRange;
    @Override
    public void initialize(DateTimeRange dateRange) {
      this.dateTimeRange = dateRange;
    }

    @Override
    public boolean isValid(Object value, ConstraintValidatorContext context) {
      if (value == null) {
        return true;
      }
      LocalDateTime ta = getByValue(value);
      if (ta == null) {
        return false;
      }

      RangeUnit unit = dateTimeRange.unit();
      int min = dateTimeRange.min();
      int max = dateTimeRange.max();

      // 忽略更小單位時，計算兩個時間的單位差值比較即可
      if (dateTimeRange.ignoreLowerUnit()) {
        long between = RangeUnit.getBetween(dateTimeRange.unit(), LocalDateTime.now(), ta);
        return between >= min && between <= max;
      }

      LocalDateTime now = LocalDateTime.now();
      return ta.isAfter((ChronoLocalDateTime<?>) RangeUnit.plus(now, unit, min))
          && ta.isBefore((ChronoLocalDateTime<?>) RangeUnit.plus(now, unit, max));
    }

    private LocalDateTime getByValue(Object value) {
      if (value instanceof LocalDateTime) {
        return (LocalDateTime) value;
      }
      if (value instanceof String) {
        try {
          return LocalDateTime.parse((String) value, DateTimeFormatter.ofPattern(dateTimeRange.pattern()));
        } catch (Exception e) {
          return null;
        }
      }
      return null;
    }
  }
}

/**
 * 日期範圍校驗，作用於 {@link LocalDate} or 字串（年月日，格式可通過pattern屬性指定，預設格式為: yyyy-MM-dd）
 *
 * @author meilin.huang
 * @date 2020-07-08 5:15 下午
 */
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.TYPE_USE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = DateRange.DateRangeValidator.class)
public @interface DateRange {

  /**
   * 最小時間範圍（為負數即為前n unit）
   */
  int min() default 0;

  int max() default Integer.MAX_VALUE;

  /**
   * 時間單位 (年月日)
   */
  RangeUnit unit() default RangeUnit.DAYS;

  /**
   * 作用於字串時，指定的格式，只能包含年月日不包含時間
   */
  String pattern() default "yyyy-MM-dd";

  /**
   * 是否忽略更小的單位，即比當前指定的unit更小的單位（如unit為Month，則忽略Days）
   */
  boolean ignoreLowerUnit() default false;

  /**
   * 錯誤提示
   */
  String message() default "日期錯誤";

  /**
   * 用於分組校驗
   */
  Class<?>[] groups() default {};
  Class<? extends Payload>[] payload() default {};
  class DateRangeValidator implements ConstraintValidator<DateRange, Object> {

    private DateRange dateRange;

    @Override
    public void initialize(DateRange dateRange) {
      this.dateRange = dateRange;
    }

    @Override
    public boolean isValid(Object value, ConstraintValidatorContext context) {
      if (value == null) {
        return true;
      }
      LocalDate ta = getByValue(value);
      if (ta == null) {
        return false;
      }
      // 忽略更小單位時，計算兩個時間的單位差值比較即可
      if (dateRange.ignoreLowerUnit()) {
        long between = RangeUnit.getBetween(dateRange.unit(), LocalDate.now(), ta);
        return between >= dateRange.min() && between <= dateRange.max();
      }

      LocalDate now = LocalDate.now();
      RangeUnit unit = dateRange.unit();
      ChronoLocalDate min = (ChronoLocalDate) RangeUnit.plus(now, unit, dateRange.min());
      ChronoLocalDate max = (ChronoLocalDate) RangeUnit.plus(now, unit, dateRange.max());
      return (ta.isAfter(min) || ta.isEqual(min))
          && (ta.isBefore(max) || ta.isEqual(max));
    }

    private LocalDate getByValue(Object value) {
      if (value instanceof LocalDate) {
        return (LocalDate) value;
      }
      if (value instanceof String) {
        try {
          return LocalDate.parse((String) value, DateTimeFormatter.ofPattern(dateRange.pattern()));
        } catch (Exception e) {
          return null;
        }
      }
      if (value instanceof LocalDateTime) {
        return ((LocalDateTime) value).toLocalDate();
      }
      return null;
    }
  }
}

/**
 * @author meilin.huang
 * @date 2020-07-09 2:06 下午
 */
public enum RangeUnit {

  /**
   * 年
   */
  YEAR,
  MONTH,
  DAYS,
  WEEKS,
  HOURS,
  MINUTES,
  SECOND;

  public static Temporal plus(Temporal date, RangeUnit unit, long value) {
    switch (unit) {
      case DAYS:
        return date.plus(value, ChronoUnit.DAYS);
      case MONTH:
        return date.plus(value, ChronoUnit.MONTHS);
      case YEAR:
        return date.plus(value, ChronoUnit.YEARS);
      case WEEKS:
        return date.plus(value, ChronoUnit.WEEKS);
      case HOURS:
        return date.plus(value, ChronoUnit.HOURS);
      case MINUTES:
        return date.plus(value, ChronoUnit.MINUTES);
      case SECOND:
        return date.plus(value, ChronoUnit.SECONDS);
      default:
        return date;
    }
  }

  public static long getBetween(RangeUnit unit, Temporal date, Temporal date2) {
    switch (unit) {
      case DAYS:
        return ChronoUnit.DAYS.between(date, date2);
      case MONTH:
        return ChronoUnit.MONTHS.between(date, date2);
      case YEAR:
        return ChronoUnit.YEARS.between(date, date2);
      case WEEKS:
        return ChronoUnit.WEEKS.between(date, date2);
      case HOURS:
        return ChronoUnit.HOURS.between(date, date2);
      case MINUTES:
        return ChronoUnit.MINUTES.between(date, date2);
      case SECOND:
        return ChronoUnit.SECONDS.between(date, date2);
      default:
        return 0;
    }
  }
}

public class ValidatorUtilsTest extends TestCase {

  public static class User {

    /**
     * createTime必須在當前日期的前一個月以及後一個月存取內，忽略day的比較
     * 即計算當前時間與傳入createTime的月份差是否在最小與最大值範圍內
     */
    @DateRange(min = -1, max = 1, unit = RangeUnit.MONTH, ignoreLowerUnit = true, message = "createTime範圍錯誤")
    String createTime = "2020-06-09";

    /**
     * date必須為當前日期時間的後一個月至後兩月內
     */
    @DateTimeRange(min = 1, max = 2, unit = RangeUnit.MONTH, message = "date範圍錯誤")
    String date = "2020-08-15 09:18:00";

    @DateTimeRange(min = 10, max = 30, message = "endTime日期範圍錯誤")
    LocalDateTime endTime = LocalDateTime.now().plusDays(30);
  }

  @Test
  public void testValidate() {
    ValidationResult validate = ValidatorUtils.validate(new User());
    System.out.println(validate);
  }
}