SpringBoot自定義validation驗(yàn)證

import?javax.validation.Constraint;
import?javax.validation.Payload;
import?java.lang.annotation.Documented;
import?java.lang.annotation.Retention;
import?java.lang.annotation.Target;

import?static?java.lang.annotation.ElementType.*;
import?static?java.lang.annotation.RetentionPolicy.RUNTIME;

@Target({METHOD,?FIELD,?ANNOTATION_TYPE,?CONSTRUCTOR,?PARAMETER})
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy?=?StringLengthValidator.class)
public?@interface?StringLength?{

????//?必須加
????String?message()?default?"{javax.validation.constraints.NotNull.message}";

????//?必須加
????Class[]?groups()?default?{};

????//?必須加
????Class[]?payload()?default?{};

????int?minLength()?default?0;

????int?maxLength()?default?16;
}

import?javax.validation.ConstraintValidator;
import?javax.validation.ConstraintValidatorContext;
import?java.util.Objects;

public?class?StringLengthValidator?implements?ConstraintValidator?{

????private?StringLength?stringLength;

????@Override
????public?void?initialize(StringLength?constraintAnnotation)?{
????????this.stringLength?=?constraintAnnotation;
????}

????@Override
????public?boolean?isValid(Object?value,?ConstraintValidatorContext?context)?{
????????if?(Objects.isNull(value))?{
????????????return?true;
????????}
????????if?(null?!=?stringLength)?{
????????????int?length?=?String.valueOf(value).length();
????????????int?maxLen?=?stringLength.maxLength(),
????????????????????minLen?=?stringLength.minLength();
????????????return?length?>=?minLen?&&?length?<=?maxLen;
????????}
????????return?false;
????}
}