javax.validation JSR验证框架

原文地址：https://blog.csdn.net/wuseyukui/article/details/81164207

JSR-303 与 hibernate-validator

Spring3支持JSR-303验证框架，JSR-303 是Java EE 6 中的一项子规范，叫做BeanValidation，官方参考实现是hibernate-validator（与Hibernate ORM 没有关系），JSR 303 用于对Java Bean 中的字段的值进行验证。

hibernate-validator实现了JSR-303规范，并扩展了一些注解，提供了一套比较完善、便捷的验证实现方式。

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>
    </dependencies>

spring-boot-starter-validation依赖关系：

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-el</artifactId>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
        </dependency>
    </dependencies>

校验bean（参数封装成对象）

POST接口 + @Valid + BindingResult 验证示例：

@Controller
@RequestMapping("/user")
public class UserController {

    /**
     * 创建用户
     * @requestBody可以将请求体中的JSON字符串绑定到相应的bean上
     * BindingResult是验证不通过的结果集合
     */
    @RequestMapping(value = "/create", method = RequestMethod.POST)
    @ResponseBody
    public String postUser(@RequestBody @Valid User user, BindingResult result) {
        if (result.hasErrors()) {
            for (ObjectError error : result.getAllErrors()) {
                System.out.println(error.getDefaultMessage());
            }
            return "error";
        }
        return "success";
    }
}

常用示例

User.java

@Data // Lombok注解，可以使我们不用再在代码里手动加get、set、toString、equals和hashCode等方法
public class User {

    @NotBlank(message = "用户名不能为空")
    private String name;

    @NotBlank(message = "年龄不能为空")
    @Range(min = 0, max = 120, message = "年龄只能从0-120岁")
    private String age;

    // 如果是空，则不校验，如果不为空，则校验
    @Pattern(regexp = "^[0-9]{4}-[0-9]{2}-[0-9]{2}$", message = "出生日期格式不正确")
    private String birthday;

}

示例2

定义Bo，使用@Valid注解为自定义对象进行级联校验：

package com.idss.common.pojo.entity.es;

import javax.validation.Valid;
import javax.validation.constraints.NotBlank;

public class UserBo {

    @NotBlank(message = "操作人id不能为空")
    private String userName;

    @NotBlank(message = "邮箱不能为空")
    private String email;

    @Valid
    private SubordinateUser subordinateUser;
}

使用验证器校验：

import javax.validation.Configuration;
import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;

public class Test{
    private static final Validator VALIDATOR;

    //获得验证器实例
    static {
        Configuration<?> config = Validation.byDefaultProvider().configure();
        ValidatorFactory factory = config.buildValidatorFactory();
        VALIDATOR = factory.getValidator();
        factory.close();
    }
    //获得验证器实例（自动关闭方式）
    static {
        try (ValidatorFactory factory = Validation.byDefaultProvider().configure().buildValidatorFactory()){
            VALIDATOR = factory.getValidator();
        }
    }

    public static void main(String []args){
        UserBo userBo = new UserBo(userName, email);
        Set<ConstraintViolation<UserBo>> validate = VALIDATOR.validate(userBo);
        if (CollectionUtils.isNotEmpty(validate)) {
            StringBuilder stringBuilder = new StringBuilder();
            validate.forEach(item -> stringBuilder.append(item.getMessage()).append(","));
            throw new RuntimeException(stringBuilder.toString().substring(0, stringBuilder.length() - 1));
        }
    }
}