实际项目中经常需要对传入的日期时间进行判断，如是否为一年内，几个月之内，几天前，几天之内等等的需求。
如要求前端传入的日期是要为当前日期一年内的某个日期，基于jdk8的LocalDateTime or LocalDate等常用的做法如下：
// 前端传字符串如‘2020-07-13 09:09:09' springmvc接收并转换为LocalDateTime类型 @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8") private LocalDateTime endTime; LocalDateTime now = LocalDateTime.now(); // jdk8校验传入日期是否为一年内 boolean flag = endTime.isBefore(now.plusYears(1))
基于上述的做法通常是比较通用的模式，如果每个日期时间都重复如此判断，略微繁琐，于是可以通过javax.validation的自定义校验注解来作用于实体属性上，借住hibernate-validate与springmvc结合来解决此类日期时间的范围校验。
DateTimeRange.java 用于LocalDateTime or String类型日期时间范围校验
@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 {
int min() default 0;
int max() default Integer.MAX_VALUE;
RangeUnit unit() default RangeUnit.DAYS;
String pattern() default "yyyy-MM-dd HH:mm:ss";
boolean ignoreLowerUnit() default false;
String message() default "日期时间错误";
Class[] groups() default {};
Class[] payload() default {};
class DateTimeRangevalidator implements ConstraintValidator {
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();
// 忽略更小单位时，计算两个时间的单位差值比较即可
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;
}
}
}
DateRange.java 用于LocalDate or String类型日期范围校验
@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 {
int min() default 0;
int max() default Integer.MAX_VALUE;
RangeUnit unit() default RangeUnit.DAYS;
String pattern() default "yyyy-MM-dd";
boolean ignoreLowerUnit() default false;
String message() default "日期错误";
Class[] groups() default {};
Class[] payload() default {};
class DateRangevalidator implements ConstraintValidator {
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;
}
// 忽略更小单位时，计算两个时间的单位差值比较即可
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;
}
}
}
RangeUnit.java 范围单位枚举，用于以上两注解的unit属性
public enum RangeUnit {
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;
}
}
}
测试类
public class ValidatorUtilsTest extends TestCase {
public static class User {
@DateRange(min = -1, max = 1, unit = RangeUnit.MONTH, ignoreLowerUnit = true, message = "createTime范围错误")
String createTime = "2020-06-09";
@DateTimeRange(min = 1, max = 2, unit = RangeUnit.MONTH, message = "date范围错误")
String date = "2020-08-15 09:18:00";
@DateTimeRange(min = 10, max = 30, message = "endTime日期范围错误")
LocalDateTime endTime = LocalDateTime.now().plusDays(30);
}
@Test
public void testValidate() {
ValidationResult validate = ValidatorUtils.validate(new User());
System.out.println(validate);
}
}
通过注解的方式对参数的日期时间属性进行范围校验，可以简化代码，去除冗余重复繁琐的代码，舒服不是一点点。当然以上是基于jdk8的localdatetime和localdate实现，如需要对Date类型范围校验，稍作修改即可。
更多方便有趣的代码可以前往个人业余总结以及练手项目中获取哈https://gitee.com/objs/mayfly
以上这篇javax.validation自定义日期范围校验注解操作就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持考高分网。
