List校验，使用原生@Size即可实现，下诉只是范例

自定义注解

@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = ListValidator.class)
public @interface ListValid {int min() default 0;int max() default Integer.MAX_VALUE;String message() default "";Class<?>[] groups() default {};Class<? extends Payload>[] payload() default {};}

自定义注解校验实现类

@Component
public class ListValidator implements ConstraintValidator<ListValid, List> {private int minLength;private int maxLength;@Overridepublic void initialize(ListValid listValid) {minLength = listValid.min();maxLength = listValid.max();}@Overridepublic boolean isValid(List target, ConstraintValidatorContext constraintValidatorContext) {int size = null == target ? 0 : target.size();if (0 != minLength && null == target) {return false;//不允许为空，List为空}if (size < minLength) {return false;//长度小于最小值}if (0 != maxLength && size > maxLength) {return false;//指定最大长度，且长度大于最大值}return true;}}

应用

 	@Valid@ListValid(min = 1,message = "请编辑后保存")private List<BO> BOList;