CharSplitQuantityValidator.java

package com.hytto.gfw.dpg.util.validation;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.validation.Constraint;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
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.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * @Description: 自定义constraint的实现，检查 Interest 的数量
 * @Author alecshan@hytto.com
 * @Date 2022/5/11
 **/
@Target({FIELD})
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {CharSplitQuantityValidator.QuantityValidatorInner.class})
public @interface CharSplitQuantityValidator {

    /**
     * 必须的属性
     * 显示 校验信息
     * 利用 {} 获取 属性值，参考了官方的message编写方式
     *
     * @see org.hibernate.validator 静态资源包里面 message 编写方式
     */
    String message() default "数量不匹配";

    /**
     * 必须的属性
     * 用于分组校验
     */
    Class<?>[] groups() default {};

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

    /**
     * 非必须
     */
    int number() default 5;

    char separatorChar() default ',';

    /**
     * 必须实现 ConstraintValidator接口
     */
    class QuantityValidatorInner implements ConstraintValidator<CharSplitQuantityValidator, String> {
        private static final Logger LOGGER = LoggerFactory.getLogger(QuantityValidatorInner.class);

        private static final int USER_PHOTO_NUMBER = 5;
        private int number;
        private char separatorChar;

        @Override
        public void initialize(CharSplitQuantityValidator constraintAnnotation) {
            this.number = constraintAnnotation.number();
            this.separatorChar = constraintAnnotation.separatorChar();
        }

        /**
         * 校验逻辑的实现
         *
         * @param value 需要校验的 值
         * @return 布尔值结果
         */
        @Override
        public boolean isValid(String value, ConstraintValidatorContext context) {
            if (StringUtils.isEmpty(value)) {
                LOGGER.debug("======> value is empty.");
                return true;
            }

            // StringUtils.split() 会丢弃空值
            String[] valueArray = StringUtils.split(value, this.separatorChar);
            int valueArrayLength = valueArray.length;
            LOGGER.debug("======> The length of the split value: {}.", valueArrayLength);
            if (valueArrayLength > this.number) {
                return false;
            }

            LOGGER.debug("======> isValid(value): true");
            return true;
        }
    }
}