javax.validation.constraints类有时候并不能满足校验需求，本文来源案例谷粒商城的视频记录。验证 Integer 类型并不能使用@Pattern，对于某个字段只能填固定的某些整数，validation并不能满足。如 private Integer showStatus;该字段只能用0或1，这时候就要用到自定义注解。

1.新建一个注解

package com.atguigu.common.valid;

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.*;

@Documented
@Constraint(
	//自定义校验器
        validatedBy = {ListValueConstraintValidator.class}
)
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.TYPE_USE})
@Retention(RetentionPolicy.RUNTIME)
public @interface ListValue {
    String message() default "{javax.validation.constraints.NotBlank.message}";

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

    Class<? extends Payload>[] payload() default {};
//定义一个数组
    int [] vals()  default {};
}

2.自定义校验器类

package com.atguigu.common.valid;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.util.HashSet;
import java.util.Set;

public class ListValueConstraintValidator implements ConstraintValidator<ListValue,Integer> {

    private Set<Integer> set=new HashSet<>();
    //初始化获取值
    @Override
    public void initialize(ListValue constraintAnnotation) {
        int[] vals = constraintAnnotation.vals();
        for (int val : vals) {
            set.add(val);
        }
    }

    //判断是否成功
    @Override
    public boolean isValid(Integer integer, ConstraintValidatorContext constraintValidatorContext) {

        return set.contains(integer);
    }
}

3.使用注解
@ListValue(vals = {0,1},message = “必须是0或1”)
private Integer showStatus;