自定义校验器注解

自定义一个注解判断提交的值是否为指定值

1、定义一个注解

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

@Documented
@Constraint(
        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 "只能在指定名称中选择";

    Class[] groups() default {};

    Class[] payload() default {};
    string[] names() default {};
}

2、自定义校验器

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


public class listValueConstraintValidator implements ConstraintValidator {

    private Set set = new HashSet<>();
    //初始化方法,将可以选择的值取出来放到set中
    @Override
    public void initialize(ListValue constraintAnnotation) {
        String[] names= constraintAnnotation.names();
        for(String name:names)
        {
            set.add(val);
        }
    }
    

    @Override
    public boolean isValid(String name, ConstraintValidatorContext constraintValidatorContext) {
        return set.contains(name);
    }
}

3、将自定义的注解放在需要属性上

@ListValue(names={"腾讯","360"})
private String companyName;