HibernateValidator自定义验证

jiezi

5 年前

在自己的摸索下对 HibernateValidator 有了初步的认识，可以使用已有的约束条件对字段做出限制，减少不要代码的出现，使代码更简洁。
但在最近的实际使用中，出现了一些无法使用框架处理的问题，例如，在第三方请求我的接口时，根据 status 字段区分不同的业务逻辑；status= 1 进行 A 逻辑处理，status= 2 进行 B 逻辑处理；在网络了检索了相关信息后，做出如下总结。

使用通用 Mapper 插件生成实体类和 mapper, 这里为了聚焦对 HibernateValidator 的使用，把关注点放在实体类 Brand 中, 在实体类中，对 status 字段添加自定义约束 @StatusConstraint

 package com.codeup.mybatisjoin.model;

import com.codeup.mybatisjoin.validation.StatusConstraint;
import lombok.Data;
import javax.persistence.Column;
import javax.persistence.Id;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;

@Data
public class Brand {
   
    @Id
    @Column(name = "brand_ID")
    private Long brandId;


    /**
     * 使用 `@NotNull` 添加约束
     */
    @Column(name = "vendor_ID")
    @NotNull(message = "[vendorId]不可为空")
    private Long vendorId;


    /**
     * 使用 `@NotBlank` 添加约束
     */
    @Column(name = "brand_name")
    @NotBlank(message = "[brandName]字段不可为空")
    private String brandName;

    private String description;


    /**
     * 自定义约束
     */
    @StatusConstraint(message = "[status]为 1 或者 2")
    private String status;
}

@StatusConstraint实现步骤和自定义注解相似

package com.codeup.mybatisjoin.validation;

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * @ProjectName: mybatisjoin
 * @Package: com.codeup.mybatisjoin.validation
 * @ClassName: StatusConstraint
 * @Author: lhc
 * @Description: 状态约束
 * @Date: 2019/8/22 下午 3:36
 */
@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
/**
 * 指出当前约束是通过 `StatusConstraintValidator.class` 来实现的
 */
@Constraint(validatedBy = StatusConstraintValidator.class)
public @interface StatusConstraint {

    /**
     * 配置 message 信息
     * @return
     */
    String message() default "违规参数";

    /**
     * 分组
     * @return
     */
    Class<?>[] groups() default {};

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

通过查看源代码里面的文档得知要要实现 ConstraintValidator 接口

@Documented
@Target({ANNOTATION_TYPE})
@Retention(RUNTIME)
public @interface Constraint {

    /**
     * {@link ConstraintValidator} classes implementing the constraint. The given 
classes
     * must reference distinct target types for a given {@link ValidationTarget}. 
If two
     * {@code ConstraintValidator}s refer to the same type, an exception will 
occur.
     * <p>
     * At most one {@code ConstraintValidator} targeting the array of parameters of
     * methods or constructors (aka cross-parameter) is accepted. If two or more
     * are present, an exception will occur.
     *
     * @return array of {@code ConstraintValidator} classes implementing the 
constraint
     */
    Class<? extends ConstraintValidator<?, ?>>[] validatedBy();
}

实现 ConstraintValidator 接口，重写 isValid() 方法，实现自己的判断逻辑

package com.codeup.mybatisjoin.validation;

import lombok.extern.slf4j.Slf4j;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

/**
 * @ProjectName: mybatisjoin
 * @Package: com.codeup.mybatisjoin.validation
 * @ClassName: StatusConstraintValidator
 * @Author: lhc
 * @Description: TODO
 * @Date: 2019/8/22 下午 3:38
 */
@Slf4j
public class StatusConstraintValidator implements 
ConstraintValidator<StatusConstraint,Object> {

    @Override
    public boolean isValid(Object value, ConstraintValidatorContext context) {String statCode = (String) value;
        // 等于 1 或 2 返回 true, 反之
        if ("1".equals(statCode) || "2".equals(statCode)) {return true;}
        return false;
    }
}

至此，对字段添加约束条件已完成。还存在一个重要的操作是对约束的校验，这里通过工具类实现

package com.codeup.mybatisjoin.validation;

import org.hibernate.validator.HibernateValidator;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import java.util.Set;

/**
 * @ProjectName: mybatisjoin
 * @Package: com.codeup.mybatisjoin.validation
 * @ClassName: ValidatorConfig
 * @Author: lhc
 * @Description: TODO
 * @Date: 2019/8/22 下午 4:31
 */
public class ValidatorUtil {


    /**
     * 配置 hibernate_validator 和快速失败模式
     */
    private static Validator validator = 
Validation.byProvider(HibernateValidator.class)
           .configure()
           .failFast(true)
           .buildValidatorFactory()
           .getValidator();


    /**
     * 参数校验，若未匹配约束，则通过已将将之前定义的 `message` 抛出
     * @param object 参数
     * @param groups 属于组
     */
    public static void result(Object object, Class<?>... groups) {
        Set<ConstraintViolation<Object>> constraintViolations = 
validator.validate(object, groups);
         if (constraintViolations.size() > 0) {String message = constraintViolations.iterator().next().getMessage();
            throw new MissingParameterException(message);
        }
    }
}

将 message 信息抛出之后，需要以更统一的方式返回给第三方，使用统一异常处理机制解决

自定义异常类 MissingParameterException

package com.codeup.mybatisjoin.validation;

public class MissingParameterException extends RuntimeException {public MissingParameterException(String message) {super(message);
    }
}

统一异常处理

package com.codeup.mybatisjoin.validation;

import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.HashMap;
import java.util.Map;


@RestControllerAdvice
public class GlobalExceptionHandler {@ExceptionHandler(MissingParameterException.class)
    public Map<String, Object> invalidParameter(MissingParameterException e) {Map<String, Object> map = new HashMap<>();
        map.put("code", 500);
        map.put("message", e.getMessage());
        return map;
    }
}

通过请求查看返回结果

package com.codeup.mybatisjoin.controller;

import com.codeup.mybatisjoin.model.Brand;
import com.codeup.mybatisjoin.validation.ValidatorUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.LinkedHashMap;
import java.util.Map;


@Slf4j
@RestController
@RequestMapping(value = "/brandConroller")
public class BrandConroller {@PostMapping(value = "/go")
    public Map<String, Object> go(@RequestBody Brand brand) {ValidatorUtil.result(brand);
        Map<String, Object> map = new LinkedHashMap<>();
        log.info("brand:{}", brand);
        return map;
    }
}

请求

// request
 {
    "brandId": 1,
    "vendorId": 1,
    "brandName": "demoData",
    "description": "demoData",
       "status": "3"
}
// response
{
    "code": 500,
    "message": "[status]为 1 或者 2"
}

前言

步骤