/**
 * @author yangyh
 * @since 2018/10/18
 */
@Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = ListStringLength.ListStringLengthValidator4List.class)
public @interface ListStringLength {

    String message() default "{org.hibernate.validator.constraints.Length.message}";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    /**
     * @return size the element must be higher or equal to
     */
    int min() default 0;

    /**
     * @return size the element must be lower or equal to
     */
    int max() default Integer.MAX_VALUE;

    /**
     * Defines several {@link ListStringLength} annotations on the same element.
     *
     * @see ListStringLength
     */
    @Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
    @Retention(RUNTIME)
    @Documented
    @interface List {

        ListStringLength[] value();
    }

    class ListStringLengthValidator4List
            implements ConstraintValidator<ListStringLength, java.util.List<String>> {

        private int min;
        private int max;

        @Override
        public void initialize(ListStringLength constraintAnnotation) {

            min = constraintAnnotation.min();
            max = constraintAnnotation.max();
        }

        @Override
        public boolean isValid(java.util.List<String> value, ConstraintValidatorContext context) {
            if (null != value && value.size() > 0) {
                for (String s : value) {
                    if (s.length() < min || s.length() > max) {
                        return false;
                    }
                }
            }
            return true;
        }
    }
}
 

遇到的坑:@Constraint這個指向的類必須是自己寫的類,我沒有指向，導致一直報錯，沒有驗證的類